From 597bc741e5ac2608e3ec0afd4256163879ab506b Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 9 Apr 2024 16:00:56 +0200 Subject: [PATCH] block/partitions/ldm: convert strncpy() to strscpy() The strncpy() here can cause a non-terminated string, which older gcc versions such as gcc-9 warn about: In function 'ldm_parse_tocblock', inlined from 'ldm_validate_tocblocks' at block/partitions/ldm.c:386:7, inlined from 'ldm_partition' at block/partitions/ldm.c:1457:7: block/partitions/ldm.c:134:2: error: 'strncpy' specified bound 16 equals destination size [-Werror=stringop-truncation] 134 | strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ block/partitions/ldm.c:145:2: error: 'strncpy' specified bound 16 equals destination size [-Werror=stringop-truncation] 145 | strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ New versions notice that the code is correct after all because of the following termination, but replacing the strncpy() with strscpy_pad() or strcpy() avoids the warning and simplifies the code at the same time. Use the padding version here to keep the existing behavior, in case the code relies on not including uninitialized data. Link: https://lkml.kernel.org/r/20240409140059.3806717-4-arnd@kernel.org Reviewed-by: Justin Stitt Signed-off-by: Arnd Bergmann Cc: Alexey Starikovskiy Cc: Bob Moore Cc: Jens Axboe Cc: Len Brown Cc: Lin Ming Cc: Masahiro Yamada Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Nathan Chancellor Cc: Nicolas Schier Cc: Rafael J. Wysocki Cc: "Richard Russon (FlatCap)" Cc: Steven Rostedt Signed-off-by: Andrew Morton --- block/partitions/ldm.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/block/partitions/ldm.c b/block/partitions/ldm.c index 38e58960ae03..2bd42fedb907 100644 --- a/block/partitions/ldm.c +++ b/block/partitions/ldm.c @@ -131,8 +131,7 @@ static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc) ldm_crit ("Cannot find TOCBLOCK, database may be corrupt."); return false; } - strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name)); - toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0; + strscpy_pad(toc->bitmap1_name, data + 0x24, sizeof(toc->bitmap1_name)); toc->bitmap1_start = get_unaligned_be64(data + 0x2E); toc->bitmap1_size = get_unaligned_be64(data + 0x36); @@ -142,8 +141,7 @@ static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc) TOC_BITMAP1, toc->bitmap1_name); return false; } - strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name)); - toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0; + strscpy_pad(toc->bitmap2_name, data + 0x46, sizeof(toc->bitmap2_name)); toc->bitmap2_start = get_unaligned_be64(data + 0x50); toc->bitmap2_size = get_unaligned_be64(data + 0x58); if (strncmp (toc->bitmap2_name, TOC_BITMAP2,