5.4-stable review patch. If anyone has any objections, please let me know.
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From: Ido Schimmel idosch@nvidia.com
[ Upstream commit 79b5b4b18bc85b19d3a518483f9abbbe6d7b3ba4 ]
The rule activity update delayed work periodically traverses the list of configured rules and queries their activity from the device.
As part of this task it accesses the entry pointed by 'ventry->entry', but this entry can be changed concurrently by the rehash delayed work, leading to a use-after-free [1].
Fix by closing the race and perform the activity query under the 'vregion->lock' mutex.
[1] BUG: KASAN: slab-use-after-free in mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140 Read of size 8 at addr ffff8881054ed808 by task kworker/0:18/181
CPU: 0 PID: 181 Comm: kworker/0:18 Not tainted 6.9.0-rc2-custom-00781-gd5ab772d32f7 #2 Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019 Workqueue: mlxsw_core mlxsw_sp_acl_rule_activity_update_work Call Trace: <TASK> dump_stack_lvl+0xc6/0x120 print_report+0xce/0x670 kasan_report+0xd7/0x110 mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140 mlxsw_sp_acl_rule_activity_update_work+0x219/0x400 process_one_work+0x8eb/0x19b0 worker_thread+0x6c9/0xf70 kthread+0x2c9/0x3b0 ret_from_fork+0x4d/0x80 ret_from_fork_asm+0x1a/0x30 </TASK>
Allocated by task 1039: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x8f/0xa0 __kmalloc+0x19c/0x360 mlxsw_sp_acl_tcam_entry_create+0x7b/0x1f0 mlxsw_sp_acl_tcam_vchunk_migrate_all+0x30d/0xb50 mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300 process_one_work+0x8eb/0x19b0 worker_thread+0x6c9/0xf70 kthread+0x2c9/0x3b0 ret_from_fork+0x4d/0x80 ret_from_fork_asm+0x1a/0x30
Freed by task 1039: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 poison_slab_object+0x102/0x170 __kasan_slab_free+0x14/0x30 kfree+0xc1/0x290 mlxsw_sp_acl_tcam_vchunk_migrate_all+0x3d7/0xb50 mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300 process_one_work+0x8eb/0x19b0 worker_thread+0x6c9/0xf70 kthread+0x2c9/0x3b0 ret_from_fork+0x4d/0x80 ret_from_fork_asm+0x1a/0x30
Fixes: 2bffc5322fd8 ("mlxsw: spectrum_acl: Don't take mutex in mlxsw_sp_acl_tcam_vregion_rehash_work()") Signed-off-by: Ido Schimmel idosch@nvidia.com Tested-by: Alexander Zubkov green@qrator.net Reviewed-by: Petr Machata petrm@nvidia.com Signed-off-by: Petr Machata petrm@nvidia.com Reviewed-by: Simon Horman horms@kernel.org Link: https://lore.kernel.org/r/1fcce0a60b231ebeb2515d91022284ba7b4ffe7a.171379710... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c index 5c0ff3d612e3c..7cd3338ed4742 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c @@ -1230,8 +1230,14 @@ mlxsw_sp_acl_tcam_ventry_activity_get(struct mlxsw_sp *mlxsw_sp, struct mlxsw_sp_acl_tcam_ventry *ventry, bool *activity) { - return mlxsw_sp_acl_tcam_entry_activity_get(mlxsw_sp, - ventry->entry, activity); + struct mlxsw_sp_acl_tcam_vregion *vregion = ventry->vchunk->vregion; + int err; + + mutex_lock(&vregion->lock); + err = mlxsw_sp_acl_tcam_entry_activity_get(mlxsw_sp, ventry->entry, + activity); + mutex_unlock(&vregion->lock); + return err; }
static int