Hi, On Thu, Mar 28, 2024 at 03:04:51PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > 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. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Thanks for the patch! This helps towards: https://github.com/KSPP/linux/issues/90 Reviewed-by: Justin Stitt <justinstitt@xxxxxxxxxx> > --- > 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, > -- > 2.39.2 > Thanks Justin
