The patch titled
Subject: block/partitions/ldm: convert strncpy() to strscpy()
has been added to the -mm mm-nonmm-unstable branch. Its filename is
block-partitions-ldm-convert-strncpy-to-strscpy.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/block-partitions-ldm-convert-strncpy-to-strscpy.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
Subject: block/partitions/ldm: convert strncpy() to strscpy()
Date: Tue, 9 Apr 2024 16:00:56 +0200
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@xxxxxxxxxx
Reviewed-by: Justin Stitt <justinstitt@xxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
Cc: Bob Moore <robert.moore@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: Lin Ming <ming.m.lin@xxxxxxxxx>
Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nicolas Schier <nicolas@xxxxxxxxx>
Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: "Richard Russon (FlatCap)" <ldm@xxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
block/partitions/ldm.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/block/partitions/ldm.c~block-partitions-ldm-convert-strncpy-to-strscpy
+++ a/block/partitions/ldm.c
@@ -131,8 +131,7 @@ static bool ldm_parse_tocblock (const u8
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
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,
_
Patches currently in -mm which might be from arnd@xxxxxxxx are
fix-missing-vmalloch-includes-fix-5.patch
kcov-avoid-clang-out-of-range-warning.patch
test_hexdump-avoid-string-truncation-warning.patch
block-partitions-ldm-convert-strncpy-to-strscpy.patch
blktrace-convert-strncpy-to-strscpy_pad.patch
