Eric Dumazet 2d327a79ee llc: only change llc->dev when bind() succeeds ... My latest patch, attempting to fix the refcount leak in a minimal way turned out to add a new bug. Whenever the bind operation fails before we attempt to grab a reference count on a device, we might release the device refcount of a prior successful bind() operation. syzbot was not happy about this [1]. Note to stable teams: Make sure commit b37a466837 ("netdevice: add the case if dev is NULL") is already present in your trees. [1] general protection fault, probably for non-canonical address 0xdffffc0000000070: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000380-0x0000000000000387] CPU: 1 PID: 3590 Comm: syz-executor361 Tainted: G W 5.17.0-syzkaller-04796-g169e77764adc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:llc_ui_connect+0x400/0xcb0 net/llc/af_llc.c:500 Code: 80 3c 02 00 0f 85 fc 07 00 00 4c 8b a5 38 05 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 80 03 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a9 07 00 00 49 8b b4 24 80 03 00 00 4c 89 f2 48 RSP: 0018:ffffc900038cfcc0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8880756eb600 RCX: 0000000000000000 RDX: 0000000000000070 RSI: ffffc900038cfe3e RDI: 0000000000000380 RBP: ffff888015ee5000 R08: 0000000000000001 R09: ffff888015ee5535 R10: ffffed1002bdcaa6 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc900038cfe37 R14: ffffc900038cfe38 R15: ffff888015ee5012 FS: 0000555555acd300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000280 CR3: 0000000077db6000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __sys_connect_file+0x155/0x1a0 net/socket.c:1900 __sys_connect+0x161/0x190 net/socket.c:1917 __do_sys_connect net/socket.c:1927 [inline] __se_sys_connect net/socket.c:1924 [inline] __x64_sys_connect+0x6f/0xb0 net/socket.c:1924 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f016acb90b9 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd417947f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f016acb90b9 RDX: 0000000000000010 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00007f016ac7d0a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f016ac7d130 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:llc_ui_connect+0x400/0xcb0 net/llc/af_llc.c:500 Fixes: 764f4eb684 ("llc: fix netdevice reference leaks in llc_ui_bind()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: 赵子轩 <beraphin@gmail.com> Cc: Stoyan Manolov <smanolov@suse.de> Link: https://lore.kernel.org/r/20220325035827.360418-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>		2022-03-25 16:55:41 -07:00
..
af_llc.c	llc: only change llc->dev when bind() succeeds	2022-03-25 16:55:41 -07:00
Kconfig	net: remove redundant 'depends on NET'	2021-01-27 17:04:12 -08:00
llc_c_ac.c	llc/snap: constify dev_addr passing	2021-10-13 09:40:46 -07:00
llc_c_ev.c	net: llc: Correct some function names in header	2021-03-26 15:24:14 -07:00
llc_c_st.c	llc: Make llc_conn_ev_qfyr_t function pointer arrays const	2014-12-10 15:21:24 -05:00
llc_conn.c	net: llc: Fix kerneldoc warnings	2020-10-30 11:34:09 -07:00
llc_core.c	llc: llc_core.c: COuple of typo fixes	2021-03-28 17:31:13 -07:00
llc_if.c	llc/snap: constify dev_addr passing	2021-10-13 09:40:46 -07:00
llc_input.c	net: llc: kerneldoc fixes	2020-07-13 17:20:39 -07:00
llc_output.c	llc/snap: constify dev_addr passing	2021-10-13 09:40:46 -07:00
llc_pdu.c	net: llc: Correct function name llc_pdu_set_pf_bit() in header	2021-03-26 15:24:14 -07:00
llc_proc.c	sock: Use sock_owned_by_user_nocheck() instead of sk_lock.owned.	2021-12-10 19:43:00 -08:00
llc_s_ac.c	net: llc: fix skb_over_panic	2021-07-27 13:05:56 +01:00
llc_s_ev.c
llc_s_st.c	llc: Make llc_sap_action_t function pointer arrays const	2014-12-10 15:21:24 -05:00
llc_sap.c	net: llc: kerneldoc fixes	2020-07-13 17:20:39 -07:00
llc_station.c	llc2: Remove redundant assignment to rc	2021-04-27 14:16:14 -07:00
Makefile	llc: fix whitespace issues	2018-07-24 14:10:42 -07:00
sysctl_net_llc.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00