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authorDavid Howells <dhowells@redhat.com>2019-08-22 13:28:43 +0100
committerDavid Howells <dhowells@redhat.com>2019-08-22 13:33:26 +0100
commita5fb8e6c02d6a518fb2b1a2b8c2471fa77b69436 (patch)
tree789dd4ce9ffac3d52183dcd1df3b1dc8260549a0
parentd1abaeb3be7b5fa6d7a1fbbd2e14e3310005c4c1 (diff)
downloadlinux-a5fb8e6c02d6a518fb2b1a2b8c2471fa77b69436.tar.bz2
afs: Fix leak in afs_lookup_cell_rcu()
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>
-rw-r--r--fs/afs/cell.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index a2a87117d262..fd5133e26a38 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -74,6 +74,7 @@ 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;
@@ -108,6 +109,9 @@ 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);
}