diff options
| author | Tristan Madani <tristan@talencesecurity.com> | 2026-05-05 14:12:58 +0300 |
|---|---|---|
| committer | Viacheslav Dubeyko <slava@dubeyko.com> | 2026-05-08 01:07:20 +0300 |
| commit | 966cb76fb2857a4242cab6ea2ea17acf818a3da7 (patch) | |
| tree | a8691d91575bfaf38ac88a71ada499aa8511c34c | |
| parent | 3f95e2661574ff13f099dd13456751933c280628 (diff) | |
| download | linux-966cb76fb2857a4242cab6ea2ea17acf818a3da7.tar.xz | |
hfs/hfsplus: fix u32 overflow in check_and_correct_requested_length
check_and_correct_requested_length() compares (off + len) against
node_size using u32 arithmetic. When the caller passes a large len
value (e.g. from an underflowed subtraction in hfs_brec_remove()),
off + len can wrap past 2^32 and produce a small result, causing the
bounds check to pass when it should fail.
For example, with off=14 and len=0xFFFFFFF2 (underflowed from
data_off - keyoffset - size in hfs_brec_remove), off + len wraps to 6,
which is less than a typical node_size of 512, so the check passes and
the subsequent memmove reads ~4GB past the node buffer.
Fix this by widening the addition to u64 before comparing against
node_size. This prevents the u32 wrap while keeping the logic
straightforward.
Reported-by: syzbot+6df204b70bf3261691c5@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6df204b70bf3261691c5
Tested-by: syzbot+6df204b70bf3261691c5@syzkaller.appspotmail.com
Reported-by: syzbot+e76bf3d19b85350571ac@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=e76bf3d19b85350571ac
Tested-by: syzbot+e76bf3d19b85350571ac@syzkaller.appspotmail.com
Fixes: a431930c9bac ("hfs: fix slab-out-of-bounds in hfs_bnode_read()")
Cc: stable@vger.kernel.org
Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Link: https://lore.kernel.org/r/20260505111300.3592757-2-tristmd@gmail.com
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
| -rw-r--r-- | fs/hfs/bnode.c | 2 | ||||
| -rw-r--r-- | fs/hfsplus/hfsplus_fs.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/fs/hfs/bnode.c b/fs/hfs/bnode.c index b0165de7640d..3a8a3878d7b0 100644 --- a/fs/hfs/bnode.c +++ b/fs/hfs/bnode.c @@ -41,7 +41,7 @@ u32 check_and_correct_requested_length(struct hfs_bnode *node, u32 off, u32 len) node_size = node->tree->node_size; - if ((off + len) > node_size) { + if ((u64)off + len > node_size) { u32 new_len = node_size - off; pr_err("requested length has been corrected: " diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h index 3545b8dbf11c..0e4268de9e60 100644 --- a/fs/hfsplus/hfsplus_fs.h +++ b/fs/hfsplus/hfsplus_fs.h @@ -600,7 +600,7 @@ u32 check_and_correct_requested_length(struct hfs_bnode *node, u32 off, u32 len) node_size = node->tree->node_size; - if ((off + len) > node_size) { + if ((u64)off + len > node_size) { u32 new_len = node_size - off; pr_err("requested length has been corrected: " |