Hello: This patch was applied to netdev/net.git (master) by Jakub Kicinski <kuba@xxxxxxxxxx>: On Wed, 7 Dec 2022 11:53:04 +0100 you wrote: > KASAN found that addr was dereferenced after br2dev_event_work was freed. > > ================================================================== > BUG: KASAN: use-after-free in qeth_l2_br2dev_worker+0x5ba/0x6b0 > Read of size 1 at addr 00000000fdcea440 by task kworker/u760:4/540 > CPU: 17 PID: 540 Comm: kworker/u760:4 Tainted: G E 6.1.0-20221128.rc7.git1.5aa3bed4ce83.300.fc36.s390x+kasan #1 > Hardware name: IBM 8561 T01 703 (LPAR) > Workqueue: 0.0.8000_event qeth_l2_br2dev_worker > Call Trace: > [<000000016944d4ce>] dump_stack_lvl+0xc6/0xf8 > [<000000016942cd9c>] print_address_description.constprop.0+0x34/0x2a0 > [<000000016942d118>] print_report+0x110/0x1f8 > [<0000000167a7bd04>] kasan_report+0xfc/0x128 > [<000000016938d79a>] qeth_l2_br2dev_worker+0x5ba/0x6b0 > [<00000001673edd1e>] process_one_work+0x76e/0x1128 > [<00000001673ee85c>] worker_thread+0x184/0x1098 > [<000000016740718a>] kthread+0x26a/0x310 > [<00000001672c606a>] __ret_from_fork+0x8a/0xe8 > [<00000001694711da>] ret_from_fork+0xa/0x40 > Allocated by task 108338: > kasan_save_stack+0x40/0x68 > kasan_set_track+0x36/0x48 > __kasan_kmalloc+0xa0/0xc0 > qeth_l2_switchdev_event+0x25a/0x738 > atomic_notifier_call_chain+0x9c/0xf8 > br_switchdev_fdb_notify+0xf4/0x110 > fdb_notify+0x122/0x180 > fdb_add_entry.constprop.0.isra.0+0x312/0x558 > br_fdb_add+0x59e/0x858 > rtnl_fdb_add+0x58a/0x928 > rtnetlink_rcv_msg+0x5f8/0x8d8 > netlink_rcv_skb+0x1f2/0x408 > netlink_unicast+0x570/0x790 > netlink_sendmsg+0x752/0xbe0 > sock_sendmsg+0xca/0x110 > ____sys_sendmsg+0x510/0x6a8 > ___sys_sendmsg+0x12a/0x180 > __sys_sendmsg+0xe6/0x168 > __do_sys_socketcall+0x3c8/0x468 > do_syscall+0x22c/0x328 > __do_syscall+0x94/0xf0 > system_call+0x82/0xb0 > Freed by task 540: > kasan_save_stack+0x40/0x68 > kasan_set_track+0x36/0x48 > kasan_save_free_info+0x4c/0x68 > ____kasan_slab_free+0x14e/0x1a8 > __kasan_slab_free+0x24/0x30 > __kmem_cache_free+0x168/0x338 > qeth_l2_br2dev_worker+0x154/0x6b0 > process_one_work+0x76e/0x1128 > worker_thread+0x184/0x1098 > kthread+0x26a/0x310 > __ret_from_fork+0x8a/0xe8 > ret_from_fork+0xa/0x40 > Last potentially related work creation: > kasan_save_stack+0x40/0x68 > __kasan_record_aux_stack+0xbe/0xd0 > insert_work+0x56/0x2e8 > __queue_work+0x4ce/0xd10 > queue_work_on+0xf4/0x100 > qeth_l2_switchdev_event+0x520/0x738 > atomic_notifier_call_chain+0x9c/0xf8 > br_switchdev_fdb_notify+0xf4/0x110 > fdb_notify+0x122/0x180 > fdb_add_entry.constprop.0.isra.0+0x312/0x558 > br_fdb_add+0x59e/0x858 > rtnl_fdb_add+0x58a/0x928 > rtnetlink_rcv_msg+0x5f8/0x8d8 > netlink_rcv_skb+0x1f2/0x408 > netlink_unicast+0x570/0x790 > netlink_sendmsg+0x752/0xbe0 > sock_sendmsg+0xca/0x110 > ____sys_sendmsg+0x510/0x6a8 > ___sys_sendmsg+0x12a/0x180 > __sys_sendmsg+0xe6/0x168 > __do_sys_socketcall+0x3c8/0x468 > do_syscall+0x22c/0x328 > __do_syscall+0x94/0xf0 > system_call+0x82/0xb0 > Second to last potentially related work creation: > kasan_save_stack+0x40/0x68 > __kasan_record_aux_stack+0xbe/0xd0 > kvfree_call_rcu+0xb2/0x760 > kernfs_unlink_open_file+0x348/0x430 > kernfs_fop_release+0xc2/0x320 > __fput+0x1ae/0x768 > task_work_run+0x1bc/0x298 > exit_to_user_mode_prepare+0x1a0/0x1a8 > __do_syscall+0x94/0xf0 > system_call+0x82/0xb0 > The buggy address belongs to the object at 00000000fdcea400 > which belongs to the cache kmalloc-96 of size 96 > The buggy address is located 64 bytes inside of > 96-byte region [00000000fdcea400, 00000000fdcea460) > The buggy address belongs to the physical page: > page:000000005a9c26e8 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xfdcea > flags: 0x3ffff00000000200(slab|node=0|zone=1|lastcpupid=0x1ffff) > raw: 3ffff00000000200 0000000000000000 0000000100000122 000000008008cc00 > raw: 0000000000000000 0020004100000000 ffffffff00000001 0000000000000000 > page dumped because: kasan: bad access detected > Memory state around the buggy address: > 00000000fdcea300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > 00000000fdcea380: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > >00000000fdcea400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ^ > 00000000fdcea480: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > 00000000fdcea500: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc > ================================================================== > > [...] Here is the summary with links: - [net,v2] s390/qeth: fix use-after-free in hsci https://git.kernel.org/netdev/net/c/ebaaadc332cd You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html