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authorAlexei Filippov <halip0503@gmail.com>2023-08-19 20:32:16 +0300
committerDave Kleikamp <dave.kleikamp@oracle.com>2023-08-29 12:25:47 -0500
commit0225e10972fa809728b8d4c1bd2772b3ec3fdb57 (patch)
treec009f0005bf638e1f9caf742db11aff4a3d70172 /fs/jfs
parent87098a0d9e42cba2ec49b56dfbf1e4944a6e7bb6 (diff)
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jfs: validate max amount of blocks before allocation.
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
Diffstat (limited to 'fs/jfs')
-rw-r--r--fs/jfs/jfs_extent.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/jfs/jfs_extent.c b/fs/jfs/jfs_extent.c
index adaa9ad50d4c..63d21822d309 100644
--- a/fs/jfs/jfs_extent.c
+++ b/fs/jfs/jfs_extent.c
@@ -311,6 +311,11 @@ 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;