diff options
author | Jiri Slaby <jslaby@suse.cz> | 2018-03-22 11:50:26 -0400 |
---|---|---|
committer | Theodore Ts'o <tytso@mit.edu> | 2018-03-22 11:50:26 -0400 |
commit | fe23cb65c2c394ea306f3714a17d46ab2e6a0af1 (patch) | |
tree | 2dd4d16379134f12cadd81d8253cef75d2c57265 /fs/ext4/ioctl.c | |
parent | 45d8ec4d9fd5468c08f2ef0b2b132bb62dc81a3d (diff) | |
download | linux-fe23cb65c2c394ea306f3714a17d46ab2e6a0af1.tar.bz2 |
ext4: fix offset overflow on 32-bit archs in ext4_iomap_begin()
ext4_iomap_begin() has a bug where offset returned in the iomap
structure will be truncated to unsigned long size. On 64-bit
architectures this is fine but on 32-bit architectures obviously not.
Not many places actually use the offset stored in the iomap structure
but one of visible failures is in SEEK_HOLE / SEEK_DATA implementation.
If we create a file like:
dd if=/dev/urandom of=file bs=1k seek=8m count=1
then
lseek64("file", 0x100000000ULL, SEEK_DATA)
wrongly returns 0x100000000 on unfixed kernel while it should return
0x200000000. Avoid the overflow by proper type cast.
Fixes: 545052e9e35a ("ext4: Switch to iomap for SEEK_HOLE / SEEK_DATA")
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org # v4.15
Diffstat (limited to 'fs/ext4/ioctl.c')
0 files changed, 0 insertions, 0 deletions