4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet edumazet@google.com
[ Upstream commit aa2b2eb3934859904c287bf5434647ba72e14c1c ]
syzbot reported an interesting trace [1] caused by a stale sk->sk_wq pointer in a closed llc socket.
In commit ff7b11aa481f ("net: socket: set sock->sk to NULL after calling proto_ops::release()") Eric Biggers hinted that some protocols are missing a sock_orphan(), we need to perform a full audit.
In net-next, I plan to clear sock->sk from sock_orphan() and amend Eric patch to add a warning.
[1] BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline] BUG: KASAN: slab-use-after-free in waitqueue_active include/linux/wait.h:127 [inline] BUG: KASAN: slab-use-after-free in sock_def_write_space_wfree net/core/sock.c:3384 [inline] BUG: KASAN: slab-use-after-free in sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468 Read of size 8 at addr ffff88802f4fc880 by task ksoftirqd/1/27
CPU: 1 PID: 27 Comm: ksoftirqd/1 Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf31 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc4/0x620 mm/kasan/report.c:488 kasan_report+0xda/0x110 mm/kasan/report.c:601 list_empty include/linux/list.h:373 [inline] waitqueue_active include/linux/wait.h:127 [inline] sock_def_write_space_wfree net/core/sock.c:3384 [inline] sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468 skb_release_head_state+0xa3/0x2b0 net/core/skbuff.c:1080 skb_release_all net/core/skbuff.c:1092 [inline] napi_consume_skb+0x119/0x2b0 net/core/skbuff.c:1404 e1000_unmap_and_free_tx_resource+0x144/0x200 drivers/net/ethernet/intel/e1000/e1000_main.c:1970 e1000_clean_tx_irq drivers/net/ethernet/intel/e1000/e1000_main.c:3860 [inline] e1000_clean+0x4a1/0x26e0 drivers/net/ethernet/intel/e1000/e1000_main.c:3801 __napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6576 napi_poll net/core/dev.c:6645 [inline] net_rx_action+0x956/0xe90 net/core/dev.c:6778 __do_softirq+0x21a/0x8de kernel/softirq.c:553 run_ksoftirqd kernel/softirq.c:921 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:913 smpboot_thread_fn+0x660/0xa10 kernel/smpboot.c:164 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 </TASK>
Allocated by task 5167: kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:314 [inline] __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc_lru+0x142/0x6f0 mm/slub.c:3879 alloc_inode_sb include/linux/fs.h:3019 [inline] sock_alloc_inode+0x25/0x1c0 net/socket.c:308 alloc_inode+0x5d/0x220 fs/inode.c:260 new_inode_pseudo+0x16/0x80 fs/inode.c:1005 sock_alloc+0x40/0x270 net/socket.c:634 __sock_create+0xbc/0x800 net/socket.c:1535 sock_create net/socket.c:1622 [inline] __sys_socket_create net/socket.c:1659 [inline] __sys_socket+0x14c/0x260 net/socket.c:1706 __do_sys_socket net/socket.c:1720 [inline] __se_sys_socket net/socket.c:1718 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1718 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b
Freed by task 0: kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640 poison_slab_object mm/kasan/common.c:241 [inline] __kasan_slab_free+0x121/0x1b0 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kmem_cache_free+0x129/0x350 mm/slub.c:4363 i_callback+0x43/0x70 fs/inode.c:249 rcu_do_batch kernel/rcu/tree.c:2158 [inline] rcu_core+0x819/0x1680 kernel/rcu/tree.c:2433 __do_softirq+0x21a/0x8de kernel/softirq.c:553
Last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 __kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:586 __call_rcu_common.constprop.0+0x9a/0x7b0 kernel/rcu/tree.c:2683 destroy_inode+0x129/0x1b0 fs/inode.c:315 iput_final fs/inode.c:1739 [inline] iput.part.0+0x560/0x7b0 fs/inode.c:1765 iput+0x5c/0x80 fs/inode.c:1755 dentry_unlink_inode+0x292/0x430 fs/dcache.c:400 __dentry_kill+0x1ca/0x5f0 fs/dcache.c:603 dput.part.0+0x4ac/0x9a0 fs/dcache.c:845 dput+0x1f/0x30 fs/dcache.c:835 __fput+0x3b9/0xb70 fs/file_table.c:384 task_work_run+0x14d/0x240 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa8a/0x2ad0 kernel/exit.c:871 do_group_exit+0xd4/0x2a0 kernel/exit.c:1020 __do_sys_exit_group kernel/exit.c:1031 [inline] __se_sys_exit_group kernel/exit.c:1029 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1029 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b
The buggy address belongs to the object at ffff88802f4fc800 which belongs to the cache sock_inode_cache of size 1408 The buggy address is located 128 bytes inside of freed 1408-byte region [ffff88802f4fc800, ffff88802f4fcd80)
The buggy address belongs to the physical page: page:ffffea0000bd3e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2f4f8 head:ffffea0000bd3e00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888013b06b40 0000000000000000 0000000000000001 raw: 0000000000000000 0000000080150015 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_RECLAIMABLE), pid 4956, tgid 4956 (sshd), ts 31423924727, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3311 __alloc_pages+0x22f/0x2440 mm/page_alloc.c:4567 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page mm/slub.c:2190 [inline] allocate_slab mm/slub.c:2354 [inline] new_slab+0xcc/0x3a0 mm/slub.c:2407 ___slab_alloc+0x4af/0x19a0 mm/slub.c:3540 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3625 __slab_alloc_node mm/slub.c:3678 [inline] slab_alloc_node mm/slub.c:3850 [inline] kmem_cache_alloc_lru+0x379/0x6f0 mm/slub.c:3879 alloc_inode_sb include/linux/fs.h:3019 [inline] sock_alloc_inode+0x25/0x1c0 net/socket.c:308 alloc_inode+0x5d/0x220 fs/inode.c:260 new_inode_pseudo+0x16/0x80 fs/inode.c:1005 sock_alloc+0x40/0x270 net/socket.c:634 __sock_create+0xbc/0x800 net/socket.c:1535 sock_create net/socket.c:1622 [inline] __sys_socket_create net/socket.c:1659 [inline] __sys_socket+0x14c/0x260 net/socket.c:1706 __do_sys_socket net/socket.c:1720 [inline] __se_sys_socket net/socket.c:1718 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1718 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b page_owner free stack trace missing
Memory state around the buggy address: ffff88802f4fc780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802f4fc800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802f4fc880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^ ffff88802f4fc900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802f4fc980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
Fixes: 43815482370c ("net: sock_def_readable() and friends RCU conversion") Reported-and-tested-by: syzbot+32b89eaa102b372ff76d@syzkaller.appspotmail.com Signed-off-by: Eric Dumazet edumazet@google.com Cc: Eric Biggers ebiggers@google.com Cc: Kuniyuki Iwashima kuniyu@amazon.com Reviewed-by: Kuniyuki Iwashima kuniyu@amazon.com Link: https://lore.kernel.org/r/20240126165532.3396702-1-edumazet@google.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/llc/af_llc.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index a5c104ea477c..fc7507ccc667 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -227,6 +227,8 @@ static int llc_ui_release(struct socket *sock) if (llc->dev) dev_put(llc->dev); sock_put(sk); + sock_orphan(sk); + sock->sk = NULL; llc_sk_free(sk); out: return 0;