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| author | Miklos Szeredi <mszeredi@redhat.com> | 2020-12-10 17:33:14 +0300 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2020-12-10 17:33:14 +0300 |
| commit | 5d069dbe8aaf2a197142558b6fb2978189ba3454 (patch) | |
| tree | 4c9ddb84e8fde7b3120e76c733fca542a5ff7ca2 /fs/fuse/inode.c | |
| parent | 9d769e6aa2524e1762e3b8681e0ed78f8acf6cad (diff) | |
| download | linux-5d069dbe8aaf2a197142558b6fb2978189ba3454.tar.xz | |
fuse: fix bad inode
Jan Kara's analysis of the syzbot report (edited):
The reproducer opens a directory on FUSE filesystem, it then attaches
dnotify mark to the open directory. After that a fuse_do_getattr() call
finds that attributes returned by the server are inconsistent, and calls
make_bad_inode() which, among other things does:
inode->i_mode = S_IFREG;
This then confuses dnotify which doesn't tear down its structures
properly and eventually crashes.
Avoid calling make_bad_inode() on a live inode: switch to a private flag on
the fuse inode. Also add the test to ops which the bad_inode_ops would
have caught.
This bug goes back to the initial merge of fuse in 2.6.14...
Reported-by: syzbot+f427adf9324b92652ccc@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Diffstat (limited to 'fs/fuse/inode.c')
| -rw-r--r-- | fs/fuse/inode.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 36ab05315828..b0e18b470e91 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -132,7 +132,7 @@ static void fuse_evict_inode(struct inode *inode) fi->forget = NULL; } } - if (S_ISREG(inode->i_mode) && !is_bad_inode(inode)) { + if (S_ISREG(inode->i_mode) && !fuse_is_bad(inode)) { WARN_ON(!list_empty(&fi->write_files)); WARN_ON(!list_empty(&fi->queued_writes)); } @@ -352,7 +352,7 @@ retry: unlock_new_inode(inode); } else if ((inode->i_mode ^ attr->mode) & S_IFMT) { /* Inode has changed type, any I/O on the old should fail */ - make_bad_inode(inode); + fuse_make_bad(inode); iput(inode); goto retry; } |