| Message ID | 20240328-strncpy-fs-pstore-blk-c-v1-1-5748cdc22a53@google.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 9dd12ed95c2d06a29a5d289c6e65589c577ef8ca |
| Headers | show |
| Series | pstore/blk: replace deprecated strncpy with strscpy | expand |
On Thu, 28 Mar 2024 20:54:16 +0000, Justin Stitt wrote: > strncpy() is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. > > We know that info-device should be NUL-terminated based on its use with > strlen(): > | static int __init mtdpstore_init(void) > | { > | int ret; > | struct mtdpstore_context *cxt = &oops_cxt; > | struct pstore_blk_config *info = &cxt->info; > | > | ret = pstore_blk_get_config(info); > | if (unlikely(ret)) > | return ret; > | > | if (strlen(info->device) == 0) { > | pr_err("mtd device must be supplied (device name is empty)\n"); > ... > > [...] Applied to for-next/pstore, thanks! [1/1] pstore/blk: replace deprecated strncpy with strscpy https://git.kernel.org/kees/c/80b735d01bbb Take care,
diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index de8cf5d75f34..65b2473e22ff 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -241,7 +241,7 @@ static int __register_pstore_blk(struct pstore_device_info *dev, /* get information of pstore/blk */ int pstore_blk_get_config(struct pstore_blk_config *info) { - strncpy(info->device, blkdev, 80); + strscpy(info->device, blkdev); info->max_reason = max_reason; info->kmsg_size = check_size(kmsg_size, 4096); info->pmsg_size = check_size(pmsg_size, 4096);
strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. We know that info-device should be NUL-terminated based on its use with strlen(): | static int __init mtdpstore_init(void) | { | int ret; | struct mtdpstore_context *cxt = &oops_cxt; | struct pstore_blk_config *info = &cxt->info; | | ret = pstore_blk_get_config(info); | if (unlikely(ret)) | return ret; | | if (strlen(info->device) == 0) { | pr_err("mtd device must be supplied (device name is empty)\n"); ... Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer. Note that this patch relies on the _new_ 2-argument version of strscpy() introduced in Commit e6584c3964f2f ("string: Allow 2-argument strscpy()"). Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt <justinstitt@google.com> --- Note: build-tested only. Found with: $ rg "strncpy\(" --- fs/pstore/blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: 928a87efa42302a23bb9554be081a28058495f22 change-id: 20240328-strncpy-fs-pstore-blk-c-8c1c0c3079f3 Best regards, -- Justin Stitt <justinstitt@google.com>