[ Upstream commit dec96fc2dcb59723e041416b8dc53e011b4bfc2e ]
In the tree search v2 ioctl we use the type size_t, which is an unsigned
long, to track the buffer size in the local variable 'buf_size'. An
unsigned long is 32 bits wide on a 32 bits architecture. The buffer size
defined in struct btrfs_ioctl_search_args_v2 is a u64, so when we later
try to copy the local variable 'buf_size' to the argument struct, when
the search returns -EOVERFLOW, we copy only 32 bits which will be a
problem on big endian systems.
Fix this by using a u64 type for the buffer sizes, not only at
btrfs_ioctl_tree_search_v2(), but also everywhere down the call chain
so that we can use the u64 at btrfs_ioctl_tree_search_v2().
Fixes: cc68a8a5a433 ("btrfs: new ioctl TREE_SEARCH_V2")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/linux-btrfs/ce6f4bd6-9453-4ffe-ba00-cee35495e10f@moroto.mountain/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9147b9ded499d9853bdf0e9804b7eaa99c4429ed ]
Jens reported the following warnings from -Wmaybe-uninitialized recent
Linus' branch.
In file included from ./include/asm-generic/rwonce.h:26,
from ./arch/arm64/include/asm/rwonce.h:71,
from ./include/linux/compiler.h:246,
from ./include/linux/export.h:5,
from ./include/linux/linkage.h:7,
from ./include/linux/kernel.h:17,
from fs/btrfs/ioctl.c:6:
In function ‘instrument_copy_from_user_before’,
inlined from ‘_copy_from_user’ at ./include/linux/uaccess.h:148:3,
inlined from ‘copy_from_user’ at ./include/linux/uaccess.h:183:7,
inlined from ‘btrfs_ioctl_space_info’ at fs/btrfs/ioctl.c:2999:6,
inlined from ‘btrfs_ioctl’ at fs/btrfs/ioctl.c:4616:10:
./include/linux/kasan-checks.h:38:27: warning: ‘space_args’ may be used
uninitialized [-Wmaybe-uninitialized]
38 | #define kasan_check_write __kasan_check_write
./include/linux/instrumented.h:129:9: note: in expansion of macro
‘kasan_check_write’
129 | kasan_check_write(to, n);
| ^~~~~~~~~~~~~~~~~
./include/linux/kasan-checks.h: In function ‘btrfs_ioctl’:
./include/linux/kasan-checks.h:20:6: note: by argument 1 of type ‘const
volatile void *’ to ‘__kasan_check_write’ declared here
20 | bool __kasan_check_write(const volatile void *p, unsigned int
size);
| ^~~~~~~~~~~~~~~~~~~
fs/btrfs/ioctl.c:2981:39: note: ‘space_args’ declared here
2981 | struct btrfs_ioctl_space_args space_args;
| ^~~~~~~~~~
In function ‘instrument_copy_from_user_before’,
inlined from ‘_copy_from_user’ at ./include/linux/uaccess.h:148:3,
inlined from ‘copy_from_user’ at ./include/linux/uaccess.h:183:7,
inlined from ‘_btrfs_ioctl_send’ at fs/btrfs/ioctl.c:4343:9,
inlined from ‘btrfs_ioctl’ at fs/btrfs/ioctl.c:4658:10:
./include/linux/kasan-checks.h:38:27: warning: ‘args32’ may be used
uninitialized [-Wmaybe-uninitialized]
38 | #define kasan_check_write __kasan_check_write
./include/linux/instrumented.h:129:9: note: in expansion of macro
‘kasan_check_write’
129 | kasan_check_write(to, n);
| ^~~~~~~~~~~~~~~~~
./include/linux/kasan-checks.h: In function ‘btrfs_ioctl’:
./include/linux/kasan-checks.h:20:6: note: by argument 1 of type ‘const
volatile void *’ to ‘__kasan_check_write’ declared here
20 | bool __kasan_check_write(const volatile void *p, unsigned int
size);
| ^~~~~~~~~~~~~~~~~~~
fs/btrfs/ioctl.c:4341:49: note: ‘args32’ declared here
4341 | struct btrfs_ioctl_send_args_32 args32;
| ^~~~~~
This was due to his config options and having KASAN turned on,
which adds some extra checks around copy_from_user(), which then
triggered the -Wmaybe-uninitialized checker for these cases.
Fix the warnings by initializing the different structs we're copying
into.
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
