diff options
| author | Edward Adam Davis <eadavis@qq.com> | 2025-08-27 09:45:55 +0800 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2025-08-27 14:29:43 +0200 |
| commit | 9d81ba6d49a7457784f0b6a71046818b86ec7e44 (patch) | |
| tree | 28f6865b462c86cf632ef866aa7338e562c0cff0 | |
| parent | bd24d2108e9c8459d2c9f3d6d910b0053887df57 (diff) | |
fuse: Block access to folio overlimit
syz reported a slab-out-of-bounds Write in fuse_dev_do_write.
When the number of bytes to be retrieved is truncated to the upper limit
by fc->max_pages and there is an offset, the oob is triggered.
Add a loop termination condition to prevent overruns.
Fixes: 3568a9569326 ("fuse: support large folios for retrieves")
Reported-by: syzbot+2d215d165f9354b9c4ea@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2d215d165f9354b9c4ea
Tested-by: syzbot+2d215d165f9354b9c4ea@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| -rw-r--r-- | fs/fuse/dev.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index e80cd8f2c049..5150aa25e64b 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1893,7 +1893,7 @@ static int fuse_retrieve(struct fuse_mount *fm, struct inode *inode, index = outarg->offset >> PAGE_SHIFT; - while (num) { + while (num && ap->num_folios < num_pages) { struct folio *folio; unsigned int folio_offset; unsigned int nr_bytes; |