From mboxrd@z Thu Jan 1 00:00:00 1970 From: Colin King Date: Wed, 21 Oct 2020 13:11:33 +0000 Subject: [PATCH][next] afs: fix a dereference on pointer cell before cell is null checked Message-Id: <20201021131133.128016-1-colin.king@canonical.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Howells , linux-afs@lists.infradead.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org From: Colin Ian King Currently the assignment of debug_id dereferences pointer cell before cell has been null checked. Fix this by removing debug_id and use cell->debug_id after cell has been null checked. Addresses-Coverity: ("Dereference before null check") Fixes: dca54a7bbb8c ("afs: Add tracing for cell refcount and active user count") Signed-off-by: Colin Ian King --- fs/afs/cell.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 52233fa6195f..4449ff100a3c 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -589,7 +589,6 @@ struct afs_cell *afs_use_cell(struct afs_cell *cell, enum afs_cell_trace reason) */ void afs_unuse_cell(struct afs_net *net, struct afs_cell *cell, enum afs_cell_trace reason) { - unsigned int debug_id = cell->debug_id; time64_t now, expire_delay; int u, a; @@ -606,7 +605,7 @@ void afs_unuse_cell(struct afs_net *net, struct afs_cell *cell, enum afs_cell_tr u = atomic_read(&cell->ref); a = atomic_dec_return(&cell->active); - trace_afs_cell(debug_id, u, a, reason); + trace_afs_cell(cell->debug_id, u, a, reason); WARN_ON(a = 0); if (a = 1) /* 'cell' may now be garbage collected. */ -- 2.27.0