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| author | Jerome Marchand | 2019-06-12 18:22:26 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2019-07-21 09:03:08 +0200 |
| commit | 042be78692aee2649c58c41ddca04e5ae3441050 (patch) | |
| tree | c88736e602b28c39e908c2672558a8751d591465 | |
| parent | pinctrl: mcp23s08: Fix add_data and irqchip_add_nested call order (diff) | |
| download | kernel-qcow2-linux-042be78692aee2649c58c41ddca04e5ae3441050.tar.gz kernel-qcow2-linux-042be78692aee2649c58c41ddca04e5ae3441050.tar.xz kernel-qcow2-linux-042be78692aee2649c58c41ddca04e5ae3441050.zip | |
dm table: don't copy from a NULL pointer in realloc_argv()
[ Upstream commit a0651926553cfe7992166432e418987760882652 ]
For the first call to realloc_argv() in dm_split_args(), old_argv is
NULL and size is zero. Then memcpy is called, with the NULL old_argv
as the source argument and a zero size argument. AFAIK, this is
undefined behavior and generates the following warning when compiled
with UBSAN on ppc64le:
In file included from ./arch/powerpc/include/asm/paca.h:19,
from ./arch/powerpc/include/asm/current.h:16,
from ./include/linux/sched.h:12,
from ./include/linux/kthread.h:6,
from drivers/md/dm-core.h:12,
from drivers/md/dm-table.c:8:
In function 'memcpy',
inlined from 'realloc_argv' at drivers/md/dm-table.c:565:3,
inlined from 'dm_split_args' at drivers/md/dm-table.c:588:9:
./include/linux/string.h:345:9: error: argument 2 null where non-null expected [-Werror=nonnull]
return __builtin_memcpy(p, q, size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/md/dm-table.c: In function 'dm_split_args':
./include/linux/string.h:345:9: note: in a call to built-in function '__builtin_memcpy'
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/md/dm-table.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index c7fe4789c40e..34ab30dd5de9 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -562,7 +562,7 @@ static char **realloc_argv(unsigned *size, char **old_argv) gfp = GFP_NOIO; } argv = kmalloc_array(new_size, sizeof(*argv), gfp); - if (argv) { + if (argv && old_argv) { memcpy(argv, old_argv, *size * sizeof(*argv)); *size = new_size; } |