Kuniyuki Iwashima 9550baada4 can: bcm: Clear bo->bcm_proc_read after remove_proc_entry(). ... [ Upstream commit 94b0818fa6 ] syzbot reported a warning in bcm_release(). [0] The blamed change fixed another warning that is triggered when connect() is issued again for a socket whose connect()ed device has been unregistered. However, if the socket is just close()d without the 2nd connect(), the remaining bo->bcm_proc_read triggers unnecessary remove_proc_entry() in bcm_release(). Let's clear bo->bcm_proc_read after remove_proc_entry() in bcm_notify(). [0] name '4986' WARNING: CPU: 0 PID: 5234 at fs/proc/generic.c:711 remove_proc_entry+0x2e7/0x5d0 fs/proc/generic.c:711 Modules linked in: CPU: 0 UID: 0 PID: 5234 Comm: syz-executor606 Not tainted 6.11.0-rc5-syzkaller-00178-g5517ae241919 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:remove_proc_entry+0x2e7/0x5d0 fs/proc/generic.c:711 Code: ff eb 05 e8 cb 1e 5e ff 48 8b 5c 24 10 48 c7 c7 e0 f7 aa 8e e8 2a 38 8e 09 90 48 c7 c7 60 3a 1b 8c 48 89 de e8 da 42 20 ff 90 <0f> 0b 90 90 48 8b 44 24 18 48 c7 44 24 40 0e 36 e0 45 49 c7 04 07 RSP: 0018:ffffc9000345fa20 EFLAGS: 00010246 RAX: 2a2d0aee2eb64600 RBX: ffff888032f1f548 RCX: ffff888029431e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000345fb08 R08: ffffffff8155b2f2 R09: 1ffff1101710519a R10: dffffc0000000000 R11: ffffed101710519b R12: ffff888011d38640 R13: 0000000000000004 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcfb52722f0 CR3: 000000000e734000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> bcm_release+0x250/0x880 net/can/bcm.c:1578 __sock_release net/socket.c:659 [inline] sock_close+0xbc/0x240 net/socket.c:1421 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcfb51ee969 Code: Unable to access opcode bytes at 0x7fcfb51ee93f. RSP: 002b:00007ffce0109ca8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fcfb51ee969 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001 RBP: 00007fcfb526f3b0 R08: ffffffffffffffb8 R09: 0000555500000000 R10: 0000555500000000 R11: 0000000000000246 R12: 00007fcfb526f3b0 R13: 0000000000000000 R14: 00007fcfb5271ee0 R15: 00007fcfb51bf160 </TASK> Fixes: 76fe372ccb ("can: bcm: Remove proc entry when dev is unregistered.") Reported-by: syzbot+0532ac7a06fb1a03187e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0532ac7a06fb1a03187e Tested-by: syzbot+0532ac7a06fb1a03187e@syzkaller.appspotmail.com Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://patch.msgid.link/20240905012237.79683-1-kuniyu@amazon.com Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-10-17 15:10:46 +02:00
..
j1939	can: j1939: use correct function name in comment	2024-10-17 15:10:44 +02:00
af_can.c	can: af_can: fix NULL pointer dereference in can_rcv_filter	2022-12-14 11:37:22 +01:00
af_can.h	can: introduce CAN midlayer private and allocate it automatically	2019-09-04 13:29:14 +02:00
bcm.c	can: bcm: Clear bo->bcm_proc_read after remove_proc_entry().	2024-10-17 15:10:46 +02:00
gw.c	can: gw: synchronize rcu operations before removing gw job entry	2021-06-19 23:53:43 +02:00
isotp.c	can: isotp: isotp_sendmsg(): fix TX state detection and wait behavior	2023-11-08 17:26:49 +01:00
Kconfig	net: remove redundant 'depends on NET'	2021-01-27 17:04:12 -08:00
Makefile	can: add ISO 15765-2:2016 transport protocol	2020-10-07 23:18:33 +02:00
proc.c	can: proc: remove unnecessary variables	2021-05-27 09:42:21 +02:00
raw.c	can: raw: add support for SO_MARK	2024-01-15 18:51:14 +01:00