This is a note to let you know that I've just added the patch titled
mlxsw: spectrum_acl_tcam: Fix possible use-after-free during activity update
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mlxsw-spectrum_acl_tcam-fix-possible-use-after-free-.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 95cece06219469eb2fa4e995818eb8e0e692dedf
Author: Ido Schimmel <idosch@xxxxxxxxxx>
Date: Mon Apr 22 17:25:56 2024 +0200
mlxsw: spectrum_acl_tcam: Fix possible use-after-free during activity update
[ 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@xxxxxxxxxx>
Tested-by: Alexander Zubkov <green@xxxxxxxxxx>
Reviewed-by: Petr Machata <petrm@xxxxxxxxxx>
Signed-off-by: Petr Machata <petrm@xxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Link: https://lore.kernel.org/r/1fcce0a60b231ebeb2515d91022284ba7b4ffe7a.1713797103.git.petrm@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
index 9c0c728bb42dc..7e69225c057de 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
@@ -1159,8 +1159,14 @@ 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
