diff options
| author | David Howells <dhowells@redhat.com> | 2019-08-22 13:28:43 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-10 10:33:52 +0100 |
| commit | 1a31b0d0ddfacf698ec54bcd52e7f8540e36fe43 (patch) | |
| tree | ea0fc5241d0091d01188099a577c57ad96f32569 | |
| parent | 111d36b6fb7ee8bc8635504aeba30bc5db0c16e1 (diff) | |
afs: Fix leak in afs_lookup_cell_rcu()
[ Upstream commit a5fb8e6c02d6a518fb2b1a2b8c2471fa77b69436 ]
Fix a leak on the cell refcount in afs_lookup_cell_rcu() due to
non-clearance of the default error in the case a NULL cell name is passed
and the workstation default cell is used.
Also put a bit at the end to make sure we don't leak a cell ref if we're
going to be returning an error.
This leak results in an assertion like the following when the kafs module is
unloaded:
AFS: Assertion failed
2 == 1 is false
0x2 == 0x1 is false
------------[ cut here ]------------
kernel BUG at fs/afs/cell.c:770!
...
RIP: 0010:afs_manage_cells+0x220/0x42f [kafs]
...
process_one_work+0x4c2/0x82c
? pool_mayday_timeout+0x1e1/0x1e1
? do_raw_spin_lock+0x134/0x175
worker_thread+0x336/0x4a6
? rescuer_thread+0x4af/0x4af
kthread+0x1de/0x1ee
? kthread_park+0xd4/0xd4
ret_from_fork+0x24/0x30
Fixes: 989782dcdc91 ("afs: Overhaul cell database management")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/afs/cell.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 6127f0fcd62c..ee07162d35c7 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -76,6 +76,7 @@ struct afs_cell *afs_lookup_cell_rcu(struct afs_net *net, cell = rcu_dereference_raw(net->ws_cell); if (cell) { afs_get_cell(cell); + ret = 0; break; } ret = -EDESTADDRREQ; @@ -110,6 +111,9 @@ struct afs_cell *afs_lookup_cell_rcu(struct afs_net *net, done_seqretry(&net->cells_lock, seq); + if (ret != 0 && cell) + afs_put_cell(net, cell); + return ret == 0 ? cell : ERR_PTR(ret); } |