diff options
| author | Xiubo Li <xiubli@redhat.com> | 2023-04-19 05:39:14 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-11 17:03:05 +0300 |
| commit | 2b2515b8095cf2149bef44383a99d5b5677f1831 (patch) | |
| tree | 3a358db69327fb3ea2c4fb0beb78d484c632969b /fs/ceph/debugfs.c | |
| parent | 9f565752b328fe53c9e42b7d4e4d89a1da63d738 (diff) | |
| download | linux-2b2515b8095cf2149bef44383a99d5b5677f1831.tar.xz | |
ceph: fix potential use-after-free bug when trimming caps
commit aaf67de78807c59c35bafb5003d4fb457c764800 upstream.
When trimming the caps and just after the 'session->s_cap_lock' is
released in ceph_iterate_session_caps() the cap maybe removed by
another thread, and when using the stale cap memory in the callbacks
it will trigger use-after-free crash.
We need to check the existence of the cap just after the 'ci->i_ceph_lock'
being acquired. And do nothing if it's already removed.
Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/43272
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Luís Henriques <lhenriques@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ceph/debugfs.c')
| -rw-r--r-- | fs/ceph/debugfs.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c index bec3c4549c07..3904333fa6c3 100644 --- a/fs/ceph/debugfs.c +++ b/fs/ceph/debugfs.c @@ -248,14 +248,20 @@ static int metrics_caps_show(struct seq_file *s, void *p) return 0; } -static int caps_show_cb(struct inode *inode, struct ceph_cap *cap, void *p) +static int caps_show_cb(struct inode *inode, int mds, void *p) { + struct ceph_inode_info *ci = ceph_inode(inode); struct seq_file *s = p; - - seq_printf(s, "0x%-17llx%-3d%-17s%-17s\n", ceph_ino(inode), - cap->session->s_mds, - ceph_cap_string(cap->issued), - ceph_cap_string(cap->implemented)); + struct ceph_cap *cap; + + spin_lock(&ci->i_ceph_lock); + cap = __get_cap_for_mds(ci, mds); + if (cap) + seq_printf(s, "0x%-17llx%-3d%-17s%-17s\n", ceph_ino(inode), + cap->session->s_mds, + ceph_cap_string(cap->issued), + ceph_cap_string(cap->implemented)); + spin_unlock(&ci->i_ceph_lock); return 0; } |