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| author | Alexei Filippov <halip0503@gmail.com> | 2023-08-19 20:32:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-09-19 13:20:15 +0300 |
| commit | 6d53616189882c9aac226794c2e51b198738ca98 (patch) | |
| tree | 49ed81605b11ed724f2f5f9dc3fc79dedd85cf9d | |
| parent | f08944e3c6962b00827de7263a9e20688e79ad84 (diff) | |
| download | linux-6d53616189882c9aac226794c2e51b198738ca98.tar.xz | |
jfs: validate max amount of blocks before allocation.
[ Upstream commit 0225e10972fa809728b8d4c1bd2772b3ec3fdb57 ]
The lack of checking bmp->db_max_freebud in extBalloc() can lead to
shift out of bounds, so this patch prevents undefined behavior, because
bmp->db_max_freebud == -1 only if there is no free space.
Signed-off-by: Aleksei Filippov <halip0503@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-and-tested-by: syzbot+5f088f29593e6b4c8db8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?id=01abadbd6ae6a08b1f1987aa61554c6b3ac19ff2
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/jfs/jfs_extent.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/jfs/jfs_extent.c b/fs/jfs/jfs_extent.c index f65bd6b35412..d4e063dbb9a0 100644 --- a/fs/jfs/jfs_extent.c +++ b/fs/jfs/jfs_extent.c @@ -508,6 +508,11 @@ extBalloc(struct inode *ip, s64 hint, s64 * nblocks, s64 * blkno) * blocks in the map. in that case, we'll start off with the * maximum free. */ + + /* give up if no space left */ + if (bmp->db_maxfreebud == -1) + return -ENOSPC; + max = (s64) 1 << bmp->db_maxfreebud; if (*nblocks >= max && *nblocks > nbperpage) nb = nblks = (max > nbperpage) ? max : nbperpage; |