| Message ID | YHaG+p5nlOXQFp1n@mwanda (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KEYS: trusted: fix a couple error pointer dereferences | expand |
On Wed, Apr 14, 2021 at 09:08:58AM +0300, Dan Carpenter wrote: > If registering "reg_shm_out" fails, then it is an error pointer and the > error handling will call tee_shm_free(reg_shm_out) which leads to an > error pointer dereference and an Oops. > > I've re-arranged it so we only free things that have been allocated > successfully. > > Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++-------------- > 1 file changed, 10 insertions(+), 14 deletions(-) > > diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c > index 2ce66c199e1d..45f96f6ed673 100644 > --- a/security/keys/trusted-keys/trusted_tee.c > +++ b/security/keys/trusted-keys/trusted_tee.c > @@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > int ret; > struct tee_ioctl_invoke_arg inv_arg; > struct tee_param param[4]; > - struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; > + struct tee_shm *reg_shm_in, *reg_shm_out; I don't have this file (trusted_tee.c) in my tree and there's no lore link here to previous what threads this depends on. Based on the context I can't verify that reg_shm_in will always be initialized before you get to the free_shm_in label. > > memset(&inv_arg, 0, sizeof(inv_arg)); > memset(¶m, 0, sizeof(param)); > @@ -84,7 +84,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > if (IS_ERR(reg_shm_out)) { > dev_err(pvt_data.dev, "blob shm register failed\n"); > ret = PTR_ERR(reg_shm_out); > - goto out; > + goto free_shm_in; > } > > inv_arg.func = TA_CMD_SEAL; > @@ -109,11 +109,9 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > p->blob_len = param[1].u.memref.size; > } > > -out: > - if (reg_shm_out) > - tee_shm_free(reg_shm_out); > - if (reg_shm_in) > - tee_shm_free(reg_shm_in); > + tee_shm_free(reg_shm_out); > +free_shm_in: > + tee_shm_free(reg_shm_in); > > return ret; > } > @@ -126,7 +124,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) > int ret; > struct tee_ioctl_invoke_arg inv_arg; > struct tee_param param[4]; > - struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; > + struct tee_shm *reg_shm_in, *reg_shm_out; > > memset(&inv_arg, 0, sizeof(inv_arg)); > memset(¶m, 0, sizeof(param)); > @@ -145,7 +143,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) > if (IS_ERR(reg_shm_out)) { > dev_err(pvt_data.dev, "key shm register failed\n"); > ret = PTR_ERR(reg_shm_out); > - goto out; > + goto free_shm_in; > } > > inv_arg.func = TA_CMD_UNSEAL; > @@ -170,11 +168,9 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) > p->key_len = param[1].u.memref.size; > } > > -out: > - if (reg_shm_out) > - tee_shm_free(reg_shm_out); > - if (reg_shm_in) > - tee_shm_free(reg_shm_in); > + tee_shm_free(reg_shm_out); > +free_shm_in: > + tee_shm_free(reg_shm_in); > > return ret; > } > -- > 2.30.2
Hi Dan, On Wed, 14 Apr 2021 at 11:39, Dan Carpenter <dan.carpenter@oracle.com> wrote: > > If registering "reg_shm_out" fails, then it is an error pointer and the > error handling will call tee_shm_free(reg_shm_out) which leads to an > error pointer dereference and an Oops. > > I've re-arranged it so we only free things that have been allocated > successfully. > > Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++-------------- > 1 file changed, 10 insertions(+), 14 deletions(-) > Thanks for fixing the error path. Although an alternative simple fix could be [1] but I liked your approach to get rid of redundant "if" checks. FWIW: Reviewed-by: Sumit Garg <sumit.garg@linaro.org> [1] diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c index 2ce66c199e1d..c4a54b0fa3eb 100644 --- a/security/keys/trusted-keys/trusted_tee.c +++ b/security/keys/trusted-keys/trusted_tee.c @@ -84,6 +84,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) if (IS_ERR(reg_shm_out)) { dev_err(pvt_data.dev, "blob shm register failed\n"); ret = PTR_ERR(reg_shm_out); + reg_shm_out = NULL; goto out; } @@ -145,6 +146,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) if (IS_ERR(reg_shm_out)) { dev_err(pvt_data.dev, "key shm register failed\n"); ret = PTR_ERR(reg_shm_out); + reg_shm_out = NULL; goto out; } -Sumit > diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c > index 2ce66c199e1d..45f96f6ed673 100644 > --- a/security/keys/trusted-keys/trusted_tee.c > +++ b/security/keys/trusted-keys/trusted_tee.c > @@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > int ret; > struct tee_ioctl_invoke_arg inv_arg; > struct tee_param param[4]; > - struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; > + struct tee_shm *reg_shm_in, *reg_shm_out; > > memset(&inv_arg, 0, sizeof(inv_arg)); > memset(¶m, 0, sizeof(param)); > @@ -84,7 +84,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > if (IS_ERR(reg_shm_out)) { > dev_err(pvt_data.dev, "blob shm register failed\n"); > ret = PTR_ERR(reg_shm_out); > - goto out; > + goto free_shm_in; > } > > inv_arg.func = TA_CMD_SEAL; > @@ -109,11 +109,9 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > p->blob_len = param[1].u.memref.size; > } > > -out: > - if (reg_shm_out) > - tee_shm_free(reg_shm_out); > - if (reg_shm_in) > - tee_shm_free(reg_shm_in); > + tee_shm_free(reg_shm_out); > +free_shm_in: > + tee_shm_free(reg_shm_in); > > return ret; > } > @@ -126,7 +124,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) > int ret; > struct tee_ioctl_invoke_arg inv_arg; > struct tee_param param[4]; > - struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; > + struct tee_shm *reg_shm_in, *reg_shm_out; > > memset(&inv_arg, 0, sizeof(inv_arg)); > memset(¶m, 0, sizeof(param)); > @@ -145,7 +143,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) > if (IS_ERR(reg_shm_out)) { > dev_err(pvt_data.dev, "key shm register failed\n"); > ret = PTR_ERR(reg_shm_out); > - goto out; > + goto free_shm_in; > } > > inv_arg.func = TA_CMD_UNSEAL; > @@ -170,11 +168,9 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) > p->key_len = param[1].u.memref.size; > } > > -out: > - if (reg_shm_out) > - tee_shm_free(reg_shm_out); > - if (reg_shm_in) > - tee_shm_free(reg_shm_in); > + tee_shm_free(reg_shm_out); > +free_shm_in: > + tee_shm_free(reg_shm_in); > > return ret; > } > -- > 2.30.2 >
Hi Serge, On Wed, 14 Apr 2021 at 19:37, Serge E. Hallyn <serge@hallyn.com> wrote: > > On Wed, Apr 14, 2021 at 09:08:58AM +0300, Dan Carpenter wrote: > > If registering "reg_shm_out" fails, then it is an error pointer and the > > error handling will call tee_shm_free(reg_shm_out) which leads to an > > error pointer dereference and an Oops. > > > > I've re-arranged it so we only free things that have been allocated > > successfully. > > > > Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys") > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > --- > > security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++-------------- > > 1 file changed, 10 insertions(+), 14 deletions(-) > > > > diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c > > index 2ce66c199e1d..45f96f6ed673 100644 > > --- a/security/keys/trusted-keys/trusted_tee.c > > +++ b/security/keys/trusted-keys/trusted_tee.c > > @@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > > int ret; > > struct tee_ioctl_invoke_arg inv_arg; > > struct tee_param param[4]; > > - struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; > > + struct tee_shm *reg_shm_in, *reg_shm_out; > > I don't have this file (trusted_tee.c) in my tree and there's no lore > link here to previous what threads this depends on. Based on the > context I can't verify that reg_shm_in will always be initialized > before you get to the free_shm_in label. > You can find trusted_tee.c here [1]. [1] https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git/tree/security/keys/trusted-keys/trusted_tee.c -Sumit > > > > memset(&inv_arg, 0, sizeof(inv_arg)); > > memset(¶m, 0, sizeof(param)); > > @@ -84,7 +84,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > > if (IS_ERR(reg_shm_out)) { > > dev_err(pvt_data.dev, "blob shm register failed\n"); > > ret = PTR_ERR(reg_shm_out); > > - goto out; > > + goto free_shm_in; > > } > > > > inv_arg.func = TA_CMD_SEAL; > > @@ -109,11 +109,9 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > > p->blob_len = param[1].u.memref.size; > > } > > > > -out: > > - if (reg_shm_out) > > - tee_shm_free(reg_shm_out); > > - if (reg_shm_in) > > - tee_shm_free(reg_shm_in); > > + tee_shm_free(reg_shm_out); > > +free_shm_in: > > + tee_shm_free(reg_shm_in); > > > > return ret; > > } > > @@ -126,7 +124,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) > > int ret; > > struct tee_ioctl_invoke_arg inv_arg; > > struct tee_param param[4]; > > - struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; > > + struct tee_shm *reg_shm_in, *reg_shm_out; > > > > memset(&inv_arg, 0, sizeof(inv_arg)); > > memset(¶m, 0, sizeof(param)); > > @@ -145,7 +143,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) > > if (IS_ERR(reg_shm_out)) { > > dev_err(pvt_data.dev, "key shm register failed\n"); > > ret = PTR_ERR(reg_shm_out); > > - goto out; > > + goto free_shm_in; > > } > > > > inv_arg.func = TA_CMD_UNSEAL; > > @@ -170,11 +168,9 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) > > p->key_len = param[1].u.memref.size; > > } > > > > -out: > > - if (reg_shm_out) > > - tee_shm_free(reg_shm_out); > > - if (reg_shm_in) > > - tee_shm_free(reg_shm_in); > > + tee_shm_free(reg_shm_out); > > +free_shm_in: > > + tee_shm_free(reg_shm_in); > > > > return ret; > > } > > -- > > 2.30.2
On Fri, Apr 16, 2021 at 06:15:58PM +0530, Sumit Garg wrote: > Hi Serge, > > On Wed, 14 Apr 2021 at 19:37, Serge E. Hallyn <serge@hallyn.com> wrote: > > > > On Wed, Apr 14, 2021 at 09:08:58AM +0300, Dan Carpenter wrote: > > > If registering "reg_shm_out" fails, then it is an error pointer and the > > > error handling will call tee_shm_free(reg_shm_out) which leads to an > > > error pointer dereference and an Oops. > > > > > > I've re-arranged it so we only free things that have been allocated > > > successfully. > > > > > > Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys") > > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > > --- > > > security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++-------------- > > > 1 file changed, 10 insertions(+), 14 deletions(-) > > > > > > diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c > > > index 2ce66c199e1d..45f96f6ed673 100644 > > > --- a/security/keys/trusted-keys/trusted_tee.c > > > +++ b/security/keys/trusted-keys/trusted_tee.c > > > @@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) > > > int ret; > > > struct tee_ioctl_invoke_arg inv_arg; > > > struct tee_param param[4]; > > > - struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; > > > + struct tee_shm *reg_shm_in, *reg_shm_out; > > > > I don't have this file (trusted_tee.c) in my tree and there's no lore > > link here to previous what threads this depends on. Based on the > > context I can't verify that reg_shm_in will always be initialized > > before you get to the free_shm_in label. > > > > You can find trusted_tee.c here [1]. > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git/tree/security/keys/trusted-keys/trusted_tee.c Thanks. Looks good then :)
diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c index 2ce66c199e1d..45f96f6ed673 100644 --- a/security/keys/trusted-keys/trusted_tee.c +++ b/security/keys/trusted-keys/trusted_tee.c @@ -65,7 +65,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) int ret; struct tee_ioctl_invoke_arg inv_arg; struct tee_param param[4]; - struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; + struct tee_shm *reg_shm_in, *reg_shm_out; memset(&inv_arg, 0, sizeof(inv_arg)); memset(¶m, 0, sizeof(param)); @@ -84,7 +84,7 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) if (IS_ERR(reg_shm_out)) { dev_err(pvt_data.dev, "blob shm register failed\n"); ret = PTR_ERR(reg_shm_out); - goto out; + goto free_shm_in; } inv_arg.func = TA_CMD_SEAL; @@ -109,11 +109,9 @@ static int trusted_tee_seal(struct trusted_key_payload *p, char *datablob) p->blob_len = param[1].u.memref.size; } -out: - if (reg_shm_out) - tee_shm_free(reg_shm_out); - if (reg_shm_in) - tee_shm_free(reg_shm_in); + tee_shm_free(reg_shm_out); +free_shm_in: + tee_shm_free(reg_shm_in); return ret; } @@ -126,7 +124,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) int ret; struct tee_ioctl_invoke_arg inv_arg; struct tee_param param[4]; - struct tee_shm *reg_shm_in = NULL, *reg_shm_out = NULL; + struct tee_shm *reg_shm_in, *reg_shm_out; memset(&inv_arg, 0, sizeof(inv_arg)); memset(¶m, 0, sizeof(param)); @@ -145,7 +143,7 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) if (IS_ERR(reg_shm_out)) { dev_err(pvt_data.dev, "key shm register failed\n"); ret = PTR_ERR(reg_shm_out); - goto out; + goto free_shm_in; } inv_arg.func = TA_CMD_UNSEAL; @@ -170,11 +168,9 @@ static int trusted_tee_unseal(struct trusted_key_payload *p, char *datablob) p->key_len = param[1].u.memref.size; } -out: - if (reg_shm_out) - tee_shm_free(reg_shm_out); - if (reg_shm_in) - tee_shm_free(reg_shm_in); + tee_shm_free(reg_shm_out); +free_shm_in: + tee_shm_free(reg_shm_in); return ret; }
If registering "reg_shm_out" fails, then it is an error pointer and the error handling will call tee_shm_free(reg_shm_out) which leads to an error pointer dereference and an Oops. I've re-arranged it so we only free things that have been allocated successfully. Fixes: 6dd95e650c8a ("KEYS: trusted: Introduce TEE based Trusted Keys") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- security/keys/trusted-keys/trusted_tee.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-)