From 9dd12ed95c2d06a29a5d289c6e65589c577ef8ca Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Thu, 28 Mar 2024 20:54:16 +0000 Subject: [PATCH] pstore/blk: replace deprecated strncpy with strscpy 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: Signed-off-by: Justin Stitt Link: https://lore.kernel.org/r/20240328-strncpy-fs-pstore-blk-c-v1-1-5748cdc22a53@google.com Signed-off-by: Kees Cook --- fs/pstore/blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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 @@ err: /* 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);