| Message ID | 1696457386-3010-15-git-send-email-wufan@linux.microsoft.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Paul Moore |
| Headers | show |
| Series | Integrity Policy Enforcement LSM (IPE) | expand |
On Oct 4, 2023 Fan Wu <wufan@linux.microsoft.com> wrote: > > Allows author of IPE policy to indicate trust for a singular dm-verity > volume, identified by roothash, through "dmverity_roothash" and all > signed dm-verity volumes, through "dmverity_signature". > > Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com> > Signed-off-by: Fan Wu <wufan@linux.microsoft.com> > --- > v2: > + No Changes > > v3: > + No changes > > v4: > + No changes > > v5: > + No changes > > v6: > + Fix an improper cleanup that can result in > a leak > > v7: > + Squash patch 08/12, 10/12 to [11/16] > > v8: > + Undo squash of 08/12, 10/12 - separating drivers/md/ from security/ > & block/ > + Use common-audit function for dmverity_signature. > + Change implementation for storing the dm-verity digest to use the > newly introduced dm_verity_digest structure introduced in patch > 14/20. > > v9: > + Adapt to the new parser > > v10: > + Select the Kconfig when all dependencies are enabled > > v11: > + No changes > --- > security/ipe/Kconfig | 18 +++++ > security/ipe/Makefile | 1 + > security/ipe/audit.c | 31 +++++++- > security/ipe/digest.c | 142 +++++++++++++++++++++++++++++++++++ > security/ipe/digest.h | 26 +++++++ > security/ipe/eval.c | 101 ++++++++++++++++++++++++- > security/ipe/eval.h | 13 ++++ > security/ipe/hooks.c | 51 +++++++++++++ > security/ipe/hooks.h | 8 ++ > security/ipe/ipe.c | 15 ++++ > security/ipe/ipe.h | 4 + > security/ipe/policy.h | 3 + > security/ipe/policy_parser.c | 24 +++++- > 13 files changed, 433 insertions(+), 4 deletions(-) > create mode 100644 security/ipe/digest.c > create mode 100644 security/ipe/digest.h ... > diff --git a/security/ipe/audit.c b/security/ipe/audit.c > index 0dd5f10c318f..b5c58655ac74 100644 > --- a/security/ipe/audit.c > +++ b/security/ipe/audit.c > @@ -13,6 +13,7 @@ > #include "hooks.h" > #include "policy.h" > #include "audit.h" > +#include "digest.h" > > #define ACTSTR(x) ((x) == IPE_ACTION_ALLOW ? "ALLOW" : "DENY") > > @@ -40,8 +41,29 @@ static const char *const audit_op_names[__IPE_OP_MAX] = { > static const char *const audit_prop_names[__IPE_PROP_MAX] = { > "boot_verified=FALSE", > "boot_verified=TRUE", > +#ifdef CONFIG_IPE_PROP_DM_VERITY > + "dmverity_roothash=", > + "dmverity_signature=FALSE", > + "dmverity_signature=TRUE", > +#endif /* CONFIG_IPE_PROP_DM_VERITY */ > }; > > +#ifdef CONFIG_IPE_PROP_DM_VERITY > +/** > + * audit_dmv_roothash - audit a roothash of a dmverity volume. > + * @ab: Supplies a pointer to the audit_buffer to append to. > + * @r: Supplies a pointer to the digest structure. > + */ > +static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh) > +{ > + ipe_digest_audit(ab, rh); > +} > +#else > +static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh) > +{ > +} > +#endif /* CONFIG_IPE_PROP_DM_VERITY */ Since the "dmverity_roothash=" field name is going to be written to the audit record regardless of CONFIG_IPE_PROP_DM_VERITY we should ensure that it has a value of "?" instead of nothing. To fix that I would suggest something like this: #else static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh) { audit_log_format(ab, "?"); } #endif /* CONFIG_IPE_PROP_DM_VERITY */ > /** > * audit_rule - audit an IPE policy rule approximation. > * @ab: Supplies a pointer to the audit_buffer to append to. > @@ -53,8 +75,13 @@ static void audit_rule(struct audit_buffer *ab, const struct ipe_rule *r) > > audit_log_format(ab, "rule=\"op=%s ", audit_op_names[r->op]); > > - list_for_each_entry(ptr, &r->props, next) > - audit_log_format(ab, "%s ", audit_prop_names[ptr->type]); > + list_for_each_entry(ptr, &r->props, next) { > + audit_log_format(ab, "%s", audit_prop_names[ptr->type]); > + if (ptr->type == IPE_PROP_DMV_ROOTHASH) > + audit_dmv_roothash(ab, ptr->value); If you wanted to avoid the roothash change above, you could change the code here so it didn't always write "dmverity_roothash=" into the audit record. > + audit_log_format(ab, " "); > + } > > audit_log_format(ab, "action=%s\"", ACTSTR(r->action)); > } > diff --git a/security/ipe/digest.c b/security/ipe/digest.c > new file mode 100644 > index 000000000000..7a42ca71880c > --- /dev/null > +++ b/security/ipe/digest.c > @@ -0,0 +1,142 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) Microsoft Corporation. All rights reserved. > + */ > + > +#include "digest.h" > + > +/** > + * ipe_digest_parse - parse a digest in IPE's policy. > + * @valstr: Supplies the string parsed from the policy. > + * @value: Supplies a pointer to be populated with the result. > + * > + * Digests in IPE are defined in a standard way: > + * <alg_name>:<hex> > + * > + * Use this function to create a property to parse the digest > + * consistently. The parsed digest will be saved in @value in IPE's > + * policy. > + * > + * Return: > + * * 0 - OK > + * * !0 - Error > + */ > +int ipe_digest_parse(const char *valstr, void **value) Why is @value void? You should make it a digest_info type or simply skip the second parameter and return a digest_info pointer. > +{ > + char *sep, *raw_digest; > + size_t raw_digest_len; > + int rc = 0; > + u8 *digest = NULL; > + struct digest_info *info = NULL; > + > + info = kzalloc(sizeof(*info), GFP_KERNEL); > + if (!info) > + return -ENOMEM; > + > + sep = strchr(valstr, ':'); > + if (!sep) { > + rc = -EBADMSG; > + goto err; > + } > + > + info->alg = kstrndup(valstr, sep - valstr, GFP_KERNEL); > + if (!info->alg) { > + rc = -ENOMEM; > + goto err; > + } > + > + raw_digest = sep + 1; > + raw_digest_len = strlen(raw_digest); > + info->raw_digest = kstrndup(raw_digest, raw_digest_len, GFP_KERNEL); Since you're running a strlen() over @raw_digest, you might as well just use kstrdup() instead of kstrndup(). > + if (!info->raw_digest) { > + rc = -ENOMEM; > + goto err_free_alg; > + } > + > + info->digest_len = (raw_digest_len + 1) / 2; > + digest = kzalloc(info->digest_len, GFP_KERNEL); > + if (!digest) { > + rc = -ENOMEM; > + goto err_free_raw; > + } > + > + rc = hex2bin(digest, raw_digest, info->digest_len); > + if (rc < 0) { > + rc = -EINVAL; > + goto err_free_raw; > + } > + > + info->digest = digest; > + *value = info; > + return 0; > + > +err_free_raw: > + kfree(info->raw_digest); > +err_free_alg: > + kfree(info->alg); > +err: > + kfree(digest); > + kfree(info); > + return rc; > +} > + > +/** > + * ipe_digest_eval - evaluate an IPE digest against another digest. > + * @expect: Supplies the policy-provided digest value. > + * @digest: Supplies the digest to compare against the policy digest value. > + * @digest_len: The length of @digest. > + * @alg: Supplies the name of the algorithm used to calculated @digest. > + * > + * Return: > + * * true - digests match > + * * false - digests do not match > + */ > +bool ipe_digest_eval(const void *expect, const u8 *digest, size_t digest_len, > + const char *alg) Similar to the above, why not make the @expect parameter a digest_info type? Also, why not pass a second digest_info parameter instead of a separate @digest, @digest_len, and @alg? > +{ > + const struct digest_info *info = (struct digest_info *)expect; > + > + return (digest_len == info->digest_len) && !strcmp(alg, info->alg) && > + (!memcmp(info->digest, digest, info->digest_len)); > +} > + > +/** > + * ipe_digest_free - free an IPE digest. > + * @value: Supplies a pointer the policy-provided digest value to free. > + */ > +void ipe_digest_free(void **value) Another digest_info parameter/type issue. > +{ > + struct digest_info *info = (struct digest_info *)(*value); > + > + if (IS_ERR_OR_NULL(info)) > + return; > + > + kfree(info->alg); > + kfree(info->raw_digest); > + kfree(info->digest); > + kfree(info); > +} > + > +/** > + * ipe_digest_audit - audit a digest that was sourced from IPE's policy. > + * @ab: Supplies the audit_buffer to append the formatted result. > + * @val: Supplies a pointer to source the audit record from. > + * > + * Digests in IPE are defined in a standard way: > + * <alg_name>:<hex> > + * > + * Use this function to create a property to audit the digest > + * consistently. > + * > + * Return: > + * 0 - OK > + * !0 - Error > + */ > +void ipe_digest_audit(struct audit_buffer *ab, const void *val) Another digest_info parameter/type issue. > +{ > + const struct digest_info *info = (struct digest_info *)val; > + > + audit_log_untrustedstring(ab, info->alg); > + audit_log_format(ab, ":"); > + audit_log_untrustedstring(ab, info->raw_digest); > +} ... > diff --git a/security/ipe/eval.c b/security/ipe/eval.c > index 78c54ff1fdd3..82ad48d7aa3d 100644 > --- a/security/ipe/eval.c > +++ b/security/ipe/eval.c > @@ -69,15 +88,89 @@ void build_eval_ctx(struct ipe_eval_ctx *ctx, > const struct file *file, > enum ipe_op_type op) > { > + struct inode *ino = NULL; > + > if (op == IPE_OP_EXEC && file) > pin_sb(FILE_SUPERBLOCK(file)); > > ctx->file = file; > ctx->op = op; > > - if (file) > + if (file) { > ctx->from_init_sb = from_pinned(FILE_SUPERBLOCK(file)); > + ino = d_real_inode(file->f_path.dentry); > + build_ipe_bdev_ctx(ctx, ino); You don't need @ino. build_ipe_bdev_ctx(ctx, d_real_inode(file->f_path.dentry)); > + } > +} > + > +#ifdef CONFIG_IPE_PROP_DM_VERITY > +/** > + * evaluate_dmv_roothash - Evaluate @ctx against a dmv roothash property. > + * @ctx: Supplies a pointer to the context being evaluated. > + * @p: Supplies a pointer to the property being evaluated. > + * > + * Return: > + * * true - The current @ctx match the @p > + * * false - The current @ctx doesn't match the @p > + */ > +static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, > + struct ipe_prop *p) > +{ > + return !!ctx->ipe_bdev && > + ipe_digest_eval(p->value, > + ctx->ipe_bdev->digest, > + ctx->ipe_bdev->digest_len, > + ctx->ipe_bdev->digest_algo); Building on my comments above in ipe_digest_eval(), if you convert it to use digest_info structs this is simplified: ipe_digest_eval(p->vlaue, ctx->ipe_bdev) > +} > + > +/** > + * evaluate_dmv_sig_false: Analyze @ctx against a dmv sig false property. > + * @ctx: Supplies a pointer to the context being evaluated. > + * @p: Supplies a pointer to the property being evaluated. > + * > + * Return: > + * * true - The current @ctx match the @p > + * * false - The current @ctx doesn't match the @p > + */ > +static bool evaluate_dmv_sig_false(const struct ipe_eval_ctx *const ctx, > + struct ipe_prop *p) > +{ > + return !ctx->ipe_bdev || (!ctx->ipe_bdev->dm_verity_signed); > +} > + > +/** > + * evaluate_dmv_sig_true: Analyze @ctx against a dmv sig true property. > + * @ctx: Supplies a pointer to the context being evaluated. > + * @p: Supplies a pointer to the property being evaluated. > + * > + * Return: > + * * true - The current @ctx match the @p > + * * false - The current @ctx doesn't match the @p > + */ > +static bool evaluate_dmv_sig_true(const struct ipe_eval_ctx *const ctx, > + struct ipe_prop *p) > +{ > + return ctx->ipe_bdev && (!!ctx->ipe_bdev->dm_verity_signed); > +} Do you need both evaluate_dmv_sig_true() and evaluate_dmv_sig_false()? If yes, you should make one call the other and return the inverse to help ensure there are no oddities. > diff --git a/security/ipe/hooks.c b/security/ipe/hooks.c > index e9386762a597..8b8031e66f36 100644 > --- a/security/ipe/hooks.c > +++ b/security/ipe/hooks.c > @@ -193,3 +196,51 @@ void ipe_sb_free_security(struct super_block *mnt_sb) > { > ipe_invalidate_pinned_sb(mnt_sb); > } > + > +#ifdef CONFIG_IPE_PROP_DM_VERITY > +/** > + * ipe_bdev_free_security - free IPE's LSM blob of block_devices. > + * @bdev: Supplies a pointer to a block_device that contains the structure > + * to free. > + */ > +void ipe_bdev_free_security(struct block_device *bdev) > +{ > + struct ipe_bdev *blob = ipe_bdev(bdev); > + > + kfree(blob->digest); > + kfree(blob->digest_algo); > +} > + > +/** > + * ipe_bdev_setsecurity - save data from a bdev to IPE's LSM blob. > + * @bdev: Supplies a pointer to a block_device that contains the LSM blob. > + * @key: Supplies the string key that uniquely identifies the value. > + * @value: Supplies the value to store. > + * @len: The length of @value. > + */ > +int ipe_bdev_setsecurity(struct block_device *bdev, const char *key, > + const void *value, size_t len) > +{ > + struct ipe_bdev *blob = ipe_bdev(bdev); > + > + if (!strcmp(key, DM_VERITY_ROOTHASH_SEC_NAME)) { > + const struct dm_verity_digest *digest = value; > + > + blob->digest = kmemdup(digest->digest, digest->digest_len, GFP_KERNEL); > + if (!blob->digest) > + return -ENOMEM; > + > + blob->digest_algo = kstrdup_const(digest->algo, GFP_KERNEL); > + if (!blob->digest_algo) > + return -ENOMEM; You need to cleanup @blob on error so you don't leak ipe_bdev::digest. > + blob->digest_len = digest->digest_len; > + return 0; > + } else if (!strcmp(key, DM_VERITY_SIGNATURE_SEC_NAME)) { > + blob->dm_verity_signed = true; > + return 0; > + } > + > + return -EOPNOTSUPP; > +} > +#endif /* CONFIG_IPE_PROP_DM_VERITY */ -- paul-moore.com
On 10/23/2023 8:52 PM, Paul Moore wrote: > On Oct 4, 2023 Fan Wu <wufan@linux.microsoft.com> wrote: >> >> Allows author of IPE policy to indicate trust for a singular dm-verity >> volume, identified by roothash, through "dmverity_roothash" and all >> signed dm-verity volumes, through "dmverity_signature". >> >> Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com> >> Signed-off-by: Fan Wu <wufan@linux.microsoft.com> >> --- ... >> security/ipe/Kconfig | 18 +++++ >> security/ipe/Makefile | 1 + >> security/ipe/audit.c | 31 +++++++- >> security/ipe/digest.c | 142 +++++++++++++++++++++++++++++++++++ >> security/ipe/digest.h | 26 +++++++ >> security/ipe/eval.c | 101 ++++++++++++++++++++++++- >> security/ipe/eval.h | 13 ++++ >> security/ipe/hooks.c | 51 +++++++++++++ >> security/ipe/hooks.h | 8 ++ >> security/ipe/ipe.c | 15 ++++ >> security/ipe/ipe.h | 4 + >> security/ipe/policy.h | 3 + >> security/ipe/policy_parser.c | 24 +++++- >> 13 files changed, 433 insertions(+), 4 deletions(-) >> create mode 100644 security/ipe/digest.c >> create mode 100644 security/ipe/digest.h > > ... > >> diff --git a/security/ipe/audit.c b/security/ipe/audit.c >> index 0dd5f10c318f..b5c58655ac74 100644 >> --- a/security/ipe/audit.c >> +++ b/security/ipe/audit.c >> @@ -13,6 +13,7 @@ >> #include "hooks.h" >> #include "policy.h" >> #include "audit.h" >> +#include "digest.h" >> >> #define ACTSTR(x) ((x) == IPE_ACTION_ALLOW ? "ALLOW" : "DENY") >> >> @@ -40,8 +41,29 @@ static const char *const audit_op_names[__IPE_OP_MAX] = { >> static const char *const audit_prop_names[__IPE_PROP_MAX] = { >> "boot_verified=FALSE", >> "boot_verified=TRUE", >> +#ifdef CONFIG_IPE_PROP_DM_VERITY >> + "dmverity_roothash=", >> + "dmverity_signature=FALSE", >> + "dmverity_signature=TRUE", >> +#endif /* CONFIG_IPE_PROP_DM_VERITY */ >> }; >> >> +#ifdef CONFIG_IPE_PROP_DM_VERITY >> +/** >> + * audit_dmv_roothash - audit a roothash of a dmverity volume. >> + * @ab: Supplies a pointer to the audit_buffer to append to. >> + * @r: Supplies a pointer to the digest structure. >> + */ >> +static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh) >> +{ >> + ipe_digest_audit(ab, rh); >> +} >> +#else >> +static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh) >> +{ >> +} >> +#endif /* CONFIG_IPE_PROP_DM_VERITY */ > > Since the "dmverity_roothash=" field name is going to be written to > the audit record regardless of CONFIG_IPE_PROP_DM_VERITY we should > ensure that it has a value of "?" instead of nothing. To fix that > I would suggest something like this: > > #else > static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh) > { > audit_log_format(ab, "?"); > } > #endif /* CONFIG_IPE_PROP_DM_VERITY */ > >> /** >> * audit_rule - audit an IPE policy rule approximation. >> * @ab: Supplies a pointer to the audit_buffer to append to. >> @@ -53,8 +75,13 @@ static void audit_rule(struct audit_buffer *ab, const struct ipe_rule *r) >> >> audit_log_format(ab, "rule=\"op=%s ", audit_op_names[r->op]); >> >> - list_for_each_entry(ptr, &r->props, next) >> - audit_log_format(ab, "%s ", audit_prop_names[ptr->type]); >> + list_for_each_entry(ptr, &r->props, next) { >> + audit_log_format(ab, "%s", audit_prop_names[ptr->type]); >> + if (ptr->type == IPE_PROP_DMV_ROOTHASH) >> + audit_dmv_roothash(ab, ptr->value); > > If you wanted to avoid the roothash change above, you could change the > code here so it didn't always write "dmverity_roothash=" into the audit > record. > Yes this sounds more reasonable to me, I will change this part to a switch case statement to avoid unnessary logging. >> + audit_log_format(ab, " "); >> + } >> >> audit_log_format(ab, "action=%s\"", ACTSTR(r->action)); >> } >> diff --git a/security/ipe/digest.c b/security/ipe/digest.c >> new file mode 100644 >> index 000000000000..7a42ca71880c >> --- /dev/null >> +++ b/security/ipe/digest.c >> @@ -0,0 +1,142 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (C) Microsoft Corporation. All rights reserved. >> + */ >> + >> +#include "digest.h" >> + >> +/** >> + * ipe_digest_parse - parse a digest in IPE's policy. >> + * @valstr: Supplies the string parsed from the policy. >> + * @value: Supplies a pointer to be populated with the result. >> + * >> + * Digests in IPE are defined in a standard way: >> + * <alg_name>:<hex> >> + * >> + * Use this function to create a property to parse the digest >> + * consistently. The parsed digest will be saved in @value in IPE's >> + * policy. >> + * >> + * Return: >> + * * 0 - OK >> + * * !0 - Error >> + */ >> +int ipe_digest_parse(const char *valstr, void **value) > > Why is @value void? You should make it a digest_info type or simply > skip the second parameter and return a digest_info pointer. > Yes it should better just return a digest_info type pointer. I will update this part. >> +{ >> + char *sep, *raw_digest; >> + size_t raw_digest_len; >> + int rc = 0; >> + u8 *digest = NULL; >> + struct digest_info *info = NULL; >> + >> + info = kzalloc(sizeof(*info), GFP_KERNEL); >> + if (!info) >> + return -ENOMEM; >> + >> + sep = strchr(valstr, ':'); >> + if (!sep) { >> + rc = -EBADMSG; >> + goto err; >> + } >> + >> + info->alg = kstrndup(valstr, sep - valstr, GFP_KERNEL); >> + if (!info->alg) { >> + rc = -ENOMEM; >> + goto err; >> + } >> + >> + raw_digest = sep + 1; >> + raw_digest_len = strlen(raw_digest); >> + info->raw_digest = kstrndup(raw_digest, raw_digest_len, GFP_KERNEL); > > Since you're running a strlen() over @raw_digest, you might as well > just use kstrdup() instead of kstrndup(). > Thanks I will update this part. >> + if (!info->raw_digest) { >> + rc = -ENOMEM; >> + goto err_free_alg; >> + } >> + >> + info->digest_len = (raw_digest_len + 1) / 2; >> + digest = kzalloc(info->digest_len, GFP_KERNEL); >> + if (!digest) { >> + rc = -ENOMEM; >> + goto err_free_raw; >> + } >> + >> + rc = hex2bin(digest, raw_digest, info->digest_len); >> + if (rc < 0) { >> + rc = -EINVAL; >> + goto err_free_raw; >> + } >> + >> + info->digest = digest; >> + *value = info; >> + return 0; >> + >> +err_free_raw: >> + kfree(info->raw_digest); >> +err_free_alg: >> + kfree(info->alg); >> +err: >> + kfree(digest); >> + kfree(info); >> + return rc; >> +} >> + >> +/** >> + * ipe_digest_eval - evaluate an IPE digest against another digest. >> + * @expect: Supplies the policy-provided digest value. >> + * @digest: Supplies the digest to compare against the policy digest value. >> + * @digest_len: The length of @digest. >> + * @alg: Supplies the name of the algorithm used to calculated @digest. >> + * >> + * Return: >> + * * true - digests match >> + * * false - digests do not match >> + */ >> +bool ipe_digest_eval(const void *expect, const u8 *digest, size_t digest_len, >> + const char *alg) > > Similar to the above, why not make the @expect parameter a digest_info > type? Also, why not pass a second digest_info parameter instead of > a separate @digest, @digest_len, and @alg? > The digest_info was inteneded to be used for policy only, which also contains a raw string of digest in the policy that can be used during audit. After second thought I start to think the raw_digest seems unnecessary and I can refactor them all to use digest_info instead. >> +{ >> + const struct digest_info *info = (struct digest_info *)expect; >> + >> + return (digest_len == info->digest_len) && !strcmp(alg, info->alg) && >> + (!memcmp(info->digest, digest, info->digest_len)); >> +} >> + >> +/** >> + * ipe_digest_free - free an IPE digest. >> + * @value: Supplies a pointer the policy-provided digest value to free. >> + */ >> +void ipe_digest_free(void **value) > > Another digest_info parameter/type issue. > >> +{ >> + struct digest_info *info = (struct digest_info *)(*value); >> + >> + if (IS_ERR_OR_NULL(info)) >> + return; >> + >> + kfree(info->alg); >> + kfree(info->raw_digest); >> + kfree(info->digest); >> + kfree(info); >> +} >> + >> +/** >> + * ipe_digest_audit - audit a digest that was sourced from IPE's policy. >> + * @ab: Supplies the audit_buffer to append the formatted result. >> + * @val: Supplies a pointer to source the audit record from. >> + * >> + * Digests in IPE are defined in a standard way: >> + * <alg_name>:<hex> >> + * >> + * Use this function to create a property to audit the digest >> + * consistently. >> + * >> + * Return: >> + * 0 - OK >> + * !0 - Error >> + */ >> +void ipe_digest_audit(struct audit_buffer *ab, const void *val) > > Another digest_info parameter/type issue. > >> +{ >> + const struct digest_info *info = (struct digest_info *)val; >> + >> + audit_log_untrustedstring(ab, info->alg); >> + audit_log_format(ab, ":"); >> + audit_log_untrustedstring(ab, info->raw_digest); >> +} > > ... > >> diff --git a/security/ipe/eval.c b/security/ipe/eval.c >> index 78c54ff1fdd3..82ad48d7aa3d 100644 >> --- a/security/ipe/eval.c >> +++ b/security/ipe/eval.c >> @@ -69,15 +88,89 @@ void build_eval_ctx(struct ipe_eval_ctx *ctx, >> const struct file *file, >> enum ipe_op_type op) >> { >> + struct inode *ino = NULL; >> + >> if (op == IPE_OP_EXEC && file) >> pin_sb(FILE_SUPERBLOCK(file)); >> >> ctx->file = file; >> ctx->op = op; >> >> - if (file) >> + if (file) { >> ctx->from_init_sb = from_pinned(FILE_SUPERBLOCK(file)); >> + ino = d_real_inode(file->f_path.dentry); >> + build_ipe_bdev_ctx(ctx, ino); > > You don't need @ino. > > build_ipe_bdev_ctx(ctx, d_real_inode(file->f_path.dentry)); > This variable will make sense in the fsverity patch, I do agree it doesn't make sense for this one. Will remove it. >> + } >> +} >> + >> +#ifdef CONFIG_IPE_PROP_DM_VERITY >> +/** >> + * evaluate_dmv_roothash - Evaluate @ctx against a dmv roothash property. >> + * @ctx: Supplies a pointer to the context being evaluated. >> + * @p: Supplies a pointer to the property being evaluated. >> + * >> + * Return: >> + * * true - The current @ctx match the @p >> + * * false - The current @ctx doesn't match the @p >> + */ >> +static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, >> + struct ipe_prop *p) >> +{ >> + return !!ctx->ipe_bdev && >> + ipe_digest_eval(p->value, >> + ctx->ipe_bdev->digest, >> + ctx->ipe_bdev->digest_len, >> + ctx->ipe_bdev->digest_algo); > > Building on my comments above in ipe_digest_eval(), if you convert it > to use digest_info structs this is simplified: > > ipe_digest_eval(p->vlaue, ctx->ipe_bdev) > Yep but the seucrity blob also contains signature information. I will make it like ipe_digest_eval(p->vlaue, ctx->ipe_bdev->dmv_digest_info) >> +} >> + >> +/** >> + * evaluate_dmv_sig_false: Analyze @ctx against a dmv sig false property. >> + * @ctx: Supplies a pointer to the context being evaluated. >> + * @p: Supplies a pointer to the property being evaluated. >> + * >> + * Return: >> + * * true - The current @ctx match the @p >> + * * false - The current @ctx doesn't match the @p >> + */ >> +static bool evaluate_dmv_sig_false(const struct ipe_eval_ctx *const ctx, >> + struct ipe_prop *p) >> +{ >> + return !ctx->ipe_bdev || (!ctx->ipe_bdev->dm_verity_signed); >> +} >> + >> +/** >> + * evaluate_dmv_sig_true: Analyze @ctx against a dmv sig true property. >> + * @ctx: Supplies a pointer to the context being evaluated. >> + * @p: Supplies a pointer to the property being evaluated. >> + * >> + * Return: >> + * * true - The current @ctx match the @p >> + * * false - The current @ctx doesn't match the @p >> + */ >> +static bool evaluate_dmv_sig_true(const struct ipe_eval_ctx *const ctx, >> + struct ipe_prop *p) >> +{ >> + return ctx->ipe_bdev && (!!ctx->ipe_bdev->dm_verity_signed); >> +} > > Do you need both evaluate_dmv_sig_true() and evaluate_dmv_sig_false()? > If yes, you should make one call the other and return the inverse to > help ensure there are no oddities. > Yes this code is redundant. I also found the ipe_prop *p variable is necssary. Will clean them up in the next version. >> diff --git a/security/ipe/hooks.c b/security/ipe/hooks.c >> index e9386762a597..8b8031e66f36 100644 >> --- a/security/ipe/hooks.c >> +++ b/security/ipe/hooks.c >> @@ -193,3 +196,51 @@ void ipe_sb_free_security(struct super_block *mnt_sb) >> { >> ipe_invalidate_pinned_sb(mnt_sb); >> } >> + >> +#ifdef CONFIG_IPE_PROP_DM_VERITY >> +/** >> + * ipe_bdev_free_security - free IPE's LSM blob of block_devices. >> + * @bdev: Supplies a pointer to a block_device that contains the structure >> + * to free. >> + */ >> +void ipe_bdev_free_security(struct block_device *bdev) >> +{ >> + struct ipe_bdev *blob = ipe_bdev(bdev); >> + >> + kfree(blob->digest); >> + kfree(blob->digest_algo); >> +} >> + >> +/** >> + * ipe_bdev_setsecurity - save data from a bdev to IPE's LSM blob. >> + * @bdev: Supplies a pointer to a block_device that contains the LSM blob. >> + * @key: Supplies the string key that uniquely identifies the value. >> + * @value: Supplies the value to store. >> + * @len: The length of @value. >> + */ >> +int ipe_bdev_setsecurity(struct block_device *bdev, const char *key, >> + const void *value, size_t len) >> +{ >> + struct ipe_bdev *blob = ipe_bdev(bdev); >> + >> + if (!strcmp(key, DM_VERITY_ROOTHASH_SEC_NAME)) { >> + const struct dm_verity_digest *digest = value; >> + >> + blob->digest = kmemdup(digest->digest, digest->digest_len, GFP_KERNEL); >> + if (!blob->digest) >> + return -ENOMEM; >> + >> + blob->digest_algo = kstrdup_const(digest->algo, GFP_KERNEL); >> + if (!blob->digest_algo) >> + return -ENOMEM; > > You need to cleanup @blob on error so you don't leak ipe_bdev::digest. > Thanks for catching that. I will fix this. -Fan >> + blob->digest_len = digest->digest_len; >> + return 0; >> + } else if (!strcmp(key, DM_VERITY_SIGNATURE_SEC_NAME)) { >> + blob->dm_verity_signed = true; >> + return 0; >> + } >> + >> + return -EOPNOTSUPP; >> +} >> +#endif /* CONFIG_IPE_PROP_DM_VERITY */ > > -- > paul-moore.com
diff --git a/security/ipe/Kconfig b/security/ipe/Kconfig index ac4d558e69d5..7afb1ce0cb99 100644 --- a/security/ipe/Kconfig +++ b/security/ipe/Kconfig @@ -8,6 +8,7 @@ menuconfig SECURITY_IPE depends on SECURITY && SECURITYFS && AUDIT && AUDITSYSCALL select PKCS7_MESSAGE_PARSER select SYSTEM_DATA_VERIFICATION + select IPE_PROP_DM_VERITY if DM_VERITY && DM_VERITY_VERIFY_ROOTHASH_SIG help This option enables the Integrity Policy Enforcement LSM allowing users to define a policy to enforce a trust-based access @@ -15,3 +16,20 @@ menuconfig SECURITY_IPE admins to reconfigure trust requirements on the fly. If unsure, answer N. + +if SECURITY_IPE +menu "IPE Trust Providers" + +config IPE_PROP_DM_VERITY + bool "Enable support for dm-verity volumes" + depends on DM_VERITY && DM_VERITY_VERIFY_ROOTHASH_SIG + help + This option enables the properties 'dmverity_signature' and + 'dmverity_roothash' in IPE policy. These properties evaluates + to TRUE when a file is evaluated against a dm-verity volume + that was mounted with a signed root-hash or the volume's + root hash matches the supplied value in the policy. + +endmenu + +endif diff --git a/security/ipe/Makefile b/security/ipe/Makefile index 2279eaa3cea3..66de53687d11 100644 --- a/security/ipe/Makefile +++ b/security/ipe/Makefile @@ -6,6 +6,7 @@ # obj-$(CONFIG_SECURITY_IPE) += \ + digest.o \ eval.o \ hooks.o \ fs.o \ diff --git a/security/ipe/audit.c b/security/ipe/audit.c index 0dd5f10c318f..b5c58655ac74 100644 --- a/security/ipe/audit.c +++ b/security/ipe/audit.c @@ -13,6 +13,7 @@ #include "hooks.h" #include "policy.h" #include "audit.h" +#include "digest.h" #define ACTSTR(x) ((x) == IPE_ACTION_ALLOW ? "ALLOW" : "DENY") @@ -40,8 +41,29 @@ static const char *const audit_op_names[__IPE_OP_MAX] = { static const char *const audit_prop_names[__IPE_PROP_MAX] = { "boot_verified=FALSE", "boot_verified=TRUE", +#ifdef CONFIG_IPE_PROP_DM_VERITY + "dmverity_roothash=", + "dmverity_signature=FALSE", + "dmverity_signature=TRUE", +#endif /* CONFIG_IPE_PROP_DM_VERITY */ }; +#ifdef CONFIG_IPE_PROP_DM_VERITY +/** + * audit_dmv_roothash - audit a roothash of a dmverity volume. + * @ab: Supplies a pointer to the audit_buffer to append to. + * @r: Supplies a pointer to the digest structure. + */ +static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh) +{ + ipe_digest_audit(ab, rh); +} +#else +static void audit_dmv_roothash(struct audit_buffer *ab, const void *rh) +{ +} +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + /** * audit_rule - audit an IPE policy rule approximation. * @ab: Supplies a pointer to the audit_buffer to append to. @@ -53,8 +75,13 @@ static void audit_rule(struct audit_buffer *ab, const struct ipe_rule *r) audit_log_format(ab, "rule=\"op=%s ", audit_op_names[r->op]); - list_for_each_entry(ptr, &r->props, next) - audit_log_format(ab, "%s ", audit_prop_names[ptr->type]); + list_for_each_entry(ptr, &r->props, next) { + audit_log_format(ab, "%s", audit_prop_names[ptr->type]); + if (ptr->type == IPE_PROP_DMV_ROOTHASH) + audit_dmv_roothash(ab, ptr->value); + + audit_log_format(ab, " "); + } audit_log_format(ab, "action=%s\"", ACTSTR(r->action)); } diff --git a/security/ipe/digest.c b/security/ipe/digest.c new file mode 100644 index 000000000000..7a42ca71880c --- /dev/null +++ b/security/ipe/digest.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) Microsoft Corporation. All rights reserved. + */ + +#include "digest.h" + +/** + * ipe_digest_parse - parse a digest in IPE's policy. + * @valstr: Supplies the string parsed from the policy. + * @value: Supplies a pointer to be populated with the result. + * + * Digests in IPE are defined in a standard way: + * <alg_name>:<hex> + * + * Use this function to create a property to parse the digest + * consistently. The parsed digest will be saved in @value in IPE's + * policy. + * + * Return: + * * 0 - OK + * * !0 - Error + */ +int ipe_digest_parse(const char *valstr, void **value) +{ + char *sep, *raw_digest; + size_t raw_digest_len; + int rc = 0; + u8 *digest = NULL; + struct digest_info *info = NULL; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + sep = strchr(valstr, ':'); + if (!sep) { + rc = -EBADMSG; + goto err; + } + + info->alg = kstrndup(valstr, sep - valstr, GFP_KERNEL); + if (!info->alg) { + rc = -ENOMEM; + goto err; + } + + raw_digest = sep + 1; + raw_digest_len = strlen(raw_digest); + info->raw_digest = kstrndup(raw_digest, raw_digest_len, GFP_KERNEL); + if (!info->raw_digest) { + rc = -ENOMEM; + goto err_free_alg; + } + + info->digest_len = (raw_digest_len + 1) / 2; + digest = kzalloc(info->digest_len, GFP_KERNEL); + if (!digest) { + rc = -ENOMEM; + goto err_free_raw; + } + + rc = hex2bin(digest, raw_digest, info->digest_len); + if (rc < 0) { + rc = -EINVAL; + goto err_free_raw; + } + + info->digest = digest; + *value = info; + return 0; + +err_free_raw: + kfree(info->raw_digest); +err_free_alg: + kfree(info->alg); +err: + kfree(digest); + kfree(info); + return rc; +} + +/** + * ipe_digest_eval - evaluate an IPE digest against another digest. + * @expect: Supplies the policy-provided digest value. + * @digest: Supplies the digest to compare against the policy digest value. + * @digest_len: The length of @digest. + * @alg: Supplies the name of the algorithm used to calculated @digest. + * + * Return: + * * true - digests match + * * false - digests do not match + */ +bool ipe_digest_eval(const void *expect, const u8 *digest, size_t digest_len, + const char *alg) +{ + const struct digest_info *info = (struct digest_info *)expect; + + return (digest_len == info->digest_len) && !strcmp(alg, info->alg) && + (!memcmp(info->digest, digest, info->digest_len)); +} + +/** + * ipe_digest_free - free an IPE digest. + * @value: Supplies a pointer the policy-provided digest value to free. + */ +void ipe_digest_free(void **value) +{ + struct digest_info *info = (struct digest_info *)(*value); + + if (IS_ERR_OR_NULL(info)) + return; + + kfree(info->alg); + kfree(info->raw_digest); + kfree(info->digest); + kfree(info); +} + +/** + * ipe_digest_audit - audit a digest that was sourced from IPE's policy. + * @ab: Supplies the audit_buffer to append the formatted result. + * @val: Supplies a pointer to source the audit record from. + * + * Digests in IPE are defined in a standard way: + * <alg_name>:<hex> + * + * Use this function to create a property to audit the digest + * consistently. + * + * Return: + * 0 - OK + * !0 - Error + */ +void ipe_digest_audit(struct audit_buffer *ab, const void *val) +{ + const struct digest_info *info = (struct digest_info *)val; + + audit_log_untrustedstring(ab, info->alg); + audit_log_format(ab, ":"); + audit_log_untrustedstring(ab, info->raw_digest); +} diff --git a/security/ipe/digest.h b/security/ipe/digest.h new file mode 100644 index 000000000000..e40ba4b2799e --- /dev/null +++ b/security/ipe/digest.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) Microsoft Corporation. All rights reserved. + */ + +#ifndef _IPE_DIGEST_H +#define _IPE_DIGEST_H + +#include "policy.h" +#include <linux/types.h> +#include <linux/audit.h> + +struct digest_info { + const char *alg; + const char *raw_digest; + const u8 *digest; + size_t digest_len; +}; + +int ipe_digest_parse(const char *valstr, void **value); +void ipe_digest_free(void **value); +void ipe_digest_audit(struct audit_buffer *ab, const void *val); +bool ipe_digest_eval(const void *expect, const u8 *digest, size_t digest_len, + const char *alg); + +#endif /* _IPE_DIGEST_H */ diff --git a/security/ipe/eval.c b/security/ipe/eval.c index 78c54ff1fdd3..82ad48d7aa3d 100644 --- a/security/ipe/eval.c +++ b/security/ipe/eval.c @@ -16,10 +16,12 @@ #include "eval.h" #include "policy.h" #include "audit.h" +#include "digest.h" struct ipe_policy __rcu *ipe_active_policy; bool success_audit; bool enforce = true; +#define INO_BLOCK_DEV(ino) ((ino)->i_sb->s_bdev) static const struct super_block *pinned_sb; static DEFINE_SPINLOCK(pin_lock); @@ -59,6 +61,23 @@ static bool from_pinned(const struct super_block *sb) return rv; } +#ifdef CONFIG_IPE_PROP_DM_VERITY +/** + * build_ipe_bdev_ctx - Build ipe_bdev field of an evaluation context. + * @ctx: Supplies a pointer to the context to be populdated. + * @ino: Supplies the inode struct of the file triggered IPE event. + */ +static void build_ipe_bdev_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino) +{ + if (INO_BLOCK_DEV(ino)) + ctx->ipe_bdev = ipe_bdev(INO_BLOCK_DEV(ino)); +} +#else +static void build_ipe_bdev_ctx(struct ipe_eval_ctx *ctx, const struct inode *const ino) +{ +} +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + /** * build_eval_ctx - Build an evaluation context. * @ctx: Supplies a pointer to the context to be populdated. @@ -69,15 +88,89 @@ void build_eval_ctx(struct ipe_eval_ctx *ctx, const struct file *file, enum ipe_op_type op) { + struct inode *ino = NULL; + if (op == IPE_OP_EXEC && file) pin_sb(FILE_SUPERBLOCK(file)); ctx->file = file; ctx->op = op; - if (file) + if (file) { ctx->from_init_sb = from_pinned(FILE_SUPERBLOCK(file)); + ino = d_real_inode(file->f_path.dentry); + build_ipe_bdev_ctx(ctx, ino); + } +} + +#ifdef CONFIG_IPE_PROP_DM_VERITY +/** + * evaluate_dmv_roothash - Evaluate @ctx against a dmv roothash property. + * @ctx: Supplies a pointer to the context being evaluated. + * @p: Supplies a pointer to the property being evaluated. + * + * Return: + * * true - The current @ctx match the @p + * * false - The current @ctx doesn't match the @p + */ +static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + return !!ctx->ipe_bdev && + ipe_digest_eval(p->value, + ctx->ipe_bdev->digest, + ctx->ipe_bdev->digest_len, + ctx->ipe_bdev->digest_algo); +} + +/** + * evaluate_dmv_sig_false: Analyze @ctx against a dmv sig false property. + * @ctx: Supplies a pointer to the context being evaluated. + * @p: Supplies a pointer to the property being evaluated. + * + * Return: + * * true - The current @ctx match the @p + * * false - The current @ctx doesn't match the @p + */ +static bool evaluate_dmv_sig_false(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + return !ctx->ipe_bdev || (!ctx->ipe_bdev->dm_verity_signed); +} + +/** + * evaluate_dmv_sig_true: Analyze @ctx against a dmv sig true property. + * @ctx: Supplies a pointer to the context being evaluated. + * @p: Supplies a pointer to the property being evaluated. + * + * Return: + * * true - The current @ctx match the @p + * * false - The current @ctx doesn't match the @p + */ +static bool evaluate_dmv_sig_true(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + return ctx->ipe_bdev && (!!ctx->ipe_bdev->dm_verity_signed); +} +#else +static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + return false; +} + +static bool evaluate_dmv_sig_false(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + return false; +} + +static bool evaluate_dmv_sig_true(const struct ipe_eval_ctx *const ctx, + struct ipe_prop *p) +{ + return false; } +#endif /* CONFIG_IPE_PROP_DM_VERITY */ /** * evaluate_property - Analyze @ctx against a property. @@ -96,6 +189,12 @@ static bool evaluate_property(const struct ipe_eval_ctx *const ctx, return !ctx->from_init_sb; case IPE_PROP_BOOT_VERIFIED_TRUE: return ctx->from_init_sb; + case IPE_PROP_DMV_ROOTHASH: + return evaluate_dmv_roothash(ctx, p); + case IPE_PROP_DMV_SIG_FALSE: + return evaluate_dmv_sig_false(ctx, p); + case IPE_PROP_DMV_SIG_TRUE: + return evaluate_dmv_sig_true(ctx, p); default: return false; } diff --git a/security/ipe/eval.h b/security/ipe/eval.h index 3f7f71452618..e575e94804a4 100644 --- a/security/ipe/eval.h +++ b/security/ipe/eval.h @@ -17,11 +17,24 @@ extern struct ipe_policy __rcu *ipe_active_policy; extern bool success_audit; extern bool enforce; +#ifdef CONFIG_IPE_PROP_DM_VERITY +struct ipe_bdev { + bool dm_verity_signed; + + const u8 *digest; + size_t digest_len; + const char *digest_algo; +}; +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + struct ipe_eval_ctx { enum ipe_op_type op; const struct file *file; bool from_init_sb; +#ifdef CONFIG_IPE_PROP_DM_VERITY + const struct ipe_bdev *ipe_bdev; +#endif /* CONFIG_IPE_PROP_DM_VERITY */ }; enum ipe_match { diff --git a/security/ipe/hooks.c b/security/ipe/hooks.c index e9386762a597..8b8031e66f36 100644 --- a/security/ipe/hooks.c +++ b/security/ipe/hooks.c @@ -7,6 +7,9 @@ #include <linux/types.h> #include <linux/binfmts.h> #include <linux/mman.h> +#include <linux/blk_types.h> +#include <linux/dm-verity.h> +#include <crypto/hash_info.h> #include "ipe.h" #include "hooks.h" @@ -193,3 +196,51 @@ void ipe_sb_free_security(struct super_block *mnt_sb) { ipe_invalidate_pinned_sb(mnt_sb); } + +#ifdef CONFIG_IPE_PROP_DM_VERITY +/** + * ipe_bdev_free_security - free IPE's LSM blob of block_devices. + * @bdev: Supplies a pointer to a block_device that contains the structure + * to free. + */ +void ipe_bdev_free_security(struct block_device *bdev) +{ + struct ipe_bdev *blob = ipe_bdev(bdev); + + kfree(blob->digest); + kfree(blob->digest_algo); +} + +/** + * ipe_bdev_setsecurity - save data from a bdev to IPE's LSM blob. + * @bdev: Supplies a pointer to a block_device that contains the LSM blob. + * @key: Supplies the string key that uniquely identifies the value. + * @value: Supplies the value to store. + * @len: The length of @value. + */ +int ipe_bdev_setsecurity(struct block_device *bdev, const char *key, + const void *value, size_t len) +{ + struct ipe_bdev *blob = ipe_bdev(bdev); + + if (!strcmp(key, DM_VERITY_ROOTHASH_SEC_NAME)) { + const struct dm_verity_digest *digest = value; + + blob->digest = kmemdup(digest->digest, digest->digest_len, GFP_KERNEL); + if (!blob->digest) + return -ENOMEM; + + blob->digest_algo = kstrdup_const(digest->algo, GFP_KERNEL); + if (!blob->digest_algo) + return -ENOMEM; + + blob->digest_len = digest->digest_len; + return 0; + } else if (!strcmp(key, DM_VERITY_SIGNATURE_SEC_NAME)) { + blob->dm_verity_signed = true; + return 0; + } + + return -EOPNOTSUPP; +} +#endif /* CONFIG_IPE_PROP_DM_VERITY */ diff --git a/security/ipe/hooks.h b/security/ipe/hooks.h index ac0cdfd9877f..d8ccb3728813 100644 --- a/security/ipe/hooks.h +++ b/security/ipe/hooks.h @@ -8,6 +8,7 @@ #include <linux/fs.h> #include <linux/binfmts.h> #include <linux/security.h> +#include <linux/blk_types.h> int ipe_bprm_check_security(struct linux_binprm *bprm); @@ -24,4 +25,11 @@ int ipe_kernel_load_data(enum kernel_load_data_id id, bool contents); void ipe_sb_free_security(struct super_block *mnt_sb); +#ifdef CONFIG_IPE_PROP_DM_VERITY +void ipe_bdev_free_security(struct block_device *bdev); + +int ipe_bdev_setsecurity(struct block_device *bdev, const char *key, + const void *value, size_t len); +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + #endif /* _IPE_HOOKS_H */ diff --git a/security/ipe/ipe.c b/security/ipe/ipe.c index 783058c06cd6..c7e8af554d35 100644 --- a/security/ipe/ipe.c +++ b/security/ipe/ipe.c @@ -5,12 +5,23 @@ #include "ipe.h" #include "hooks.h" +#include "eval.h" bool ipe_enabled; static struct lsm_blob_sizes ipe_blobs __ro_after_init = { +#ifdef CONFIG_IPE_PROP_DM_VERITY + .lbs_bdev = sizeof(struct ipe_bdev), +#endif /* CONFIG_IPE_PROP_DM_VERITY */ }; +#ifdef CONFIG_IPE_PROP_DM_VERITY +struct ipe_bdev *ipe_bdev(struct block_device *b) +{ + return b->security + ipe_blobs.lbs_bdev; +} +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + static struct security_hook_list ipe_hooks[] __ro_after_init = { LSM_HOOK_INIT(bprm_check_security, ipe_bprm_check_security), LSM_HOOK_INIT(mmap_file, ipe_mmap_file), @@ -18,6 +29,10 @@ static struct security_hook_list ipe_hooks[] __ro_after_init = { LSM_HOOK_INIT(kernel_read_file, ipe_kernel_read_file), LSM_HOOK_INIT(kernel_load_data, ipe_kernel_load_data), LSM_HOOK_INIT(sb_free_security, ipe_sb_free_security), +#ifdef CONFIG_IPE_PROP_DM_VERITY + LSM_HOOK_INIT(bdev_free_security, ipe_bdev_free_security), + LSM_HOOK_INIT(bdev_setsecurity, ipe_bdev_setsecurity), +#endif }; /** diff --git a/security/ipe/ipe.h b/security/ipe/ipe.h index 6dec06403eee..4e8d1a440c4b 100644 --- a/security/ipe/ipe.h +++ b/security/ipe/ipe.h @@ -15,4 +15,8 @@ extern bool ipe_enabled; +#ifdef CONFIG_IPE_PROP_DM_VERITY +struct ipe_bdev *ipe_bdev(struct block_device *b); +#endif /* CONFIG_IPE_PROP_DM_VERITY */ + #endif /* _IPE_H */ diff --git a/security/ipe/policy.h b/security/ipe/policy.h index 32e5e0b941eb..13e5c40e9204 100644 --- a/security/ipe/policy.h +++ b/security/ipe/policy.h @@ -33,6 +33,9 @@ enum ipe_action_type { enum ipe_prop_type { IPE_PROP_BOOT_VERIFIED_FALSE, IPE_PROP_BOOT_VERIFIED_TRUE, + IPE_PROP_DMV_ROOTHASH, + IPE_PROP_DMV_SIG_FALSE, + IPE_PROP_DMV_SIG_TRUE, __IPE_PROP_MAX }; diff --git a/security/ipe/policy_parser.c b/security/ipe/policy_parser.c index ee7646de72ed..3acb1d681f65 100644 --- a/security/ipe/policy_parser.c +++ b/security/ipe/policy_parser.c @@ -10,6 +10,7 @@ #include "policy.h" #include "policy_parser.h" +#include "digest.h" #define START_COMMENT '#' #define IPE_POLICY_DELIM " \t" @@ -216,6 +217,7 @@ static void free_rule(struct ipe_rule *r) list_for_each_entry_safe(p, t, &r->props, next) { list_del(&p->next); + ipe_digest_free(&p->value); kfree(p); } @@ -268,6 +270,11 @@ static enum ipe_action_type parse_action(char *t) static const match_table_t property_tokens = { {IPE_PROP_BOOT_VERIFIED_FALSE, "boot_verified=FALSE"}, {IPE_PROP_BOOT_VERIFIED_TRUE, "boot_verified=TRUE"}, +#ifdef CONFIG_IPE_PROP_DM_VERITY + {IPE_PROP_DMV_ROOTHASH, "dmverity_roothash=%s"}, + {IPE_PROP_DMV_SIG_FALSE, "dmverity_signature=FALSE"}, + {IPE_PROP_DMV_SIG_TRUE, "dmverity_signature=TRUE"}, +#endif /* CONFIG_IPE_PROP_DM_VERITY */ {IPE_PROP_INVALID, NULL} }; @@ -287,6 +294,7 @@ static int parse_property(char *t, struct ipe_rule *r) struct ipe_prop *p = NULL; int rc = 0; int token; + char *dup = NULL; p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) @@ -295,8 +303,20 @@ static int parse_property(char *t, struct ipe_rule *r) token = match_token(t, property_tokens, args); switch (token) { + case IPE_PROP_DMV_ROOTHASH: + dup = match_strdup(&args[0]); + if (!dup) { + rc = -ENOMEM; + goto err; + } + rc = ipe_digest_parse(dup, &p->value); + if (rc) + goto err; + fallthrough; case IPE_PROP_BOOT_VERIFIED_FALSE: case IPE_PROP_BOOT_VERIFIED_TRUE: + case IPE_PROP_DMV_SIG_FALSE: + case IPE_PROP_DMV_SIG_TRUE: p->type = token; break; default: @@ -307,10 +327,12 @@ static int parse_property(char *t, struct ipe_rule *r) goto err; list_add_tail(&p->next, &r->props); +out: + kfree(dup); return rc; err: kfree(p); - return rc; + goto out; } /**