* BUG: unable to handle kernel NULL pointer dereference in inet_release @ 2020-02-25 8:08 syzbot 2020-02-25 8:15 ` Eric Dumazet 0 siblings, 1 reply; 4+ messages in thread From: syzbot @ 2020-02-25 8:08 UTC (permalink / raw) To: andriin, ast, bpf, daniel, davem, kafai, kuba, kuznet, linux-kernel, netdev, songliubraving, syzkaller-bugs, yhs, yoshfuji Hello, syzbot found the following crash on: HEAD commit: 54dedb5b Merge tag 'for-linus-5.6-rc3-tag' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=168f7de9e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=3e57a6b450fb9883 dashboard link: https://syzkaller.appspot.com/bug?extid=1938db17e275e85dc328 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1681fe09e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+1938db17e275e85dc328@syzkaller.appspotmail.com BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD a0113067 P4D a0113067 PUD a8771067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 10686 Comm: syz-executor.0 Not tainted 5.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246 RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40 RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5 R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098 R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000 FS: 00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: inet_release+0x165/0x1c0 net/ipv4/af_inet.c:427 __sock_release net/socket.c:605 [inline] sock_close+0xe1/0x260 net/socket.c:1283 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x176/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:164 [inline] prepare_exit_to_usermode+0x480/0x5b0 arch/x86/entry/common.c:195 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c429 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2ae75dac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: 0000000000000000 RBX: 00007f2ae75db6d4 RCX: 000000000045c429 RDX: 0000000000000001 RSI: 000000000000011a RDI: 0000000000000004 RBP: 000000000076bf20 R08: 0000000000000038 R09: 0000000000000000 R10: 0000000020000180 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000a9d R14: 00000000004ccfb4 R15: 000000000076bf2c Modules linked in: CR2: 0000000000000000 ---[ end trace 82567b5207e87bae ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246 RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40 RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5 R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098 R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000 FS: 00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: BUG: unable to handle kernel NULL pointer dereference in inet_release 2020-02-25 8:08 BUG: unable to handle kernel NULL pointer dereference in inet_release syzbot @ 2020-02-25 8:15 ` Eric Dumazet 2020-02-25 18:23 ` Eric Dumazet 0 siblings, 1 reply; 4+ messages in thread From: Eric Dumazet @ 2020-02-25 8:15 UTC (permalink / raw) To: syzbot, andriin, ast, bpf, daniel, davem, kafai, kuba, kuznet, linux-kernel, netdev, songliubraving, syzkaller-bugs, yhs On 2/25/20 12:08 AM, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 54dedb5b Merge tag 'for-linus-5.6-rc3-tag' of git://git.ke.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=168f7de9e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=3e57a6b450fb9883 > dashboard link: https://syzkaller.appspot.com/bug?extid=1938db17e275e85dc328 > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1681fe09e00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+1938db17e275e85dc328@syzkaller.appspotmail.com > > BUG: kernel NULL pointer dereference, address: 0000000000000000 > #PF: supervisor instruction fetch in kernel mode > #PF: error_code(0x0010) - not-present page > PGD a0113067 P4D a0113067 PUD a8771067 PMD 0 > Oops: 0010 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 10686 Comm: syz-executor.0 Not tainted 5.6.0-rc2-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:0x0 > Code: Bad RIP value. > RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246 > RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40 > RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5 > R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098 > R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000 > FS: 00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > inet_release+0x165/0x1c0 net/ipv4/af_inet.c:427 > __sock_release net/socket.c:605 [inline] > sock_close+0xe1/0x260 net/socket.c:1283 > __fput+0x2e4/0x740 fs/file_table.c:280 > ____fput+0x15/0x20 fs/file_table.c:313 > task_work_run+0x176/0x1b0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop arch/x86/entry/common.c:164 [inline] > prepare_exit_to_usermode+0x480/0x5b0 arch/x86/entry/common.c:195 > syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278 > do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x45c429 > Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007f2ae75dac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 > RAX: 0000000000000000 RBX: 00007f2ae75db6d4 RCX: 000000000045c429 > RDX: 0000000000000001 RSI: 000000000000011a RDI: 0000000000000004 > RBP: 000000000076bf20 R08: 0000000000000038 R09: 0000000000000000 > R10: 0000000020000180 R11: 0000000000000246 R12: 00000000ffffffff > R13: 0000000000000a9d R14: 00000000004ccfb4 R15: 000000000076bf2c > Modules linked in: > CR2: 0000000000000000 > ---[ end trace 82567b5207e87bae ]--- > RIP: 0010:0x0 > Code: Bad RIP value. > RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246 > RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40 > RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5 > R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098 > R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000 > FS: 00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches > Note to ULP maintainers Probably the code for IPV6_ADDRFORM needs some care if a TCP socket got ULP enabled ? ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: BUG: unable to handle kernel NULL pointer dereference in inet_release 2020-02-25 8:15 ` Eric Dumazet @ 2020-02-25 18:23 ` Eric Dumazet 2020-02-26 11:22 ` Jakub Sitnicki 0 siblings, 1 reply; 4+ messages in thread From: Eric Dumazet @ 2020-02-25 18:23 UTC (permalink / raw) To: syzbot, andriin, ast, bpf, daniel, davem, kafai, kuba, kuznet, linux-kernel, netdev, songliubraving, syzkaller-bugs, yhs On 2/25/20 12:15 AM, Eric Dumazet wrote: > > > On 2/25/20 12:08 AM, syzbot wrote: >> Hello, >> >> syzbot found the following crash on: >> >> HEAD commit: 54dedb5b Merge tag 'for-linus-5.6-rc3-tag' of git://git.ke.. >> git tree: upstream >> console output: https://syzkaller.appspot.com/x/log.txt?x=168f7de9e00000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=3e57a6b450fb9883 >> dashboard link: https://syzkaller.appspot.com/bug?extid=1938db17e275e85dc328 >> compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1681fe09e00000 >> >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+1938db17e275e85dc328@syzkaller.appspotmail.com >> >> BUG: kernel NULL pointer dereference, address: 0000000000000000 >> #PF: supervisor instruction fetch in kernel mode >> #PF: error_code(0x0010) - not-present page >> PGD a0113067 P4D a0113067 PUD a8771067 PMD 0 >> Oops: 0010 [#1] PREEMPT SMP KASAN >> CPU: 0 PID: 10686 Comm: syz-executor.0 Not tainted 5.6.0-rc2-syzkaller #0 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >> RIP: 0010:0x0 >> Code: Bad RIP value. >> RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246 >> RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000 >> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40 >> RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5 >> R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098 >> R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000 >> FS: 00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> Call Trace: >> inet_release+0x165/0x1c0 net/ipv4/af_inet.c:427 >> __sock_release net/socket.c:605 [inline] >> sock_close+0xe1/0x260 net/socket.c:1283 >> __fput+0x2e4/0x740 fs/file_table.c:280 >> ____fput+0x15/0x20 fs/file_table.c:313 >> task_work_run+0x176/0x1b0 kernel/task_work.c:113 >> tracehook_notify_resume include/linux/tracehook.h:188 [inline] >> exit_to_usermode_loop arch/x86/entry/common.c:164 [inline] >> prepare_exit_to_usermode+0x480/0x5b0 arch/x86/entry/common.c:195 >> syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278 >> do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304 >> entry_SYSCALL_64_after_hwframe+0x49/0xbe >> RIP: 0033:0x45c429 >> Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 >> RSP: 002b:00007f2ae75dac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 >> RAX: 0000000000000000 RBX: 00007f2ae75db6d4 RCX: 000000000045c429 >> RDX: 0000000000000001 RSI: 000000000000011a RDI: 0000000000000004 >> RBP: 000000000076bf20 R08: 0000000000000038 R09: 0000000000000000 >> R10: 0000000020000180 R11: 0000000000000246 R12: 00000000ffffffff >> R13: 0000000000000a9d R14: 00000000004ccfb4 R15: 000000000076bf2c >> Modules linked in: >> CR2: 0000000000000000 >> ---[ end trace 82567b5207e87bae ]--- >> RIP: 0010:0x0 >> Code: Bad RIP value. >> RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246 >> RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000 >> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40 >> RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5 >> R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098 >> R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000 >> FS: 00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> >> >> --- >> This bug is generated by a bot. It may contain errors. >> See https://goo.gl/tpsmEJ for more information about syzbot. >> syzbot engineers can be reached at syzkaller@googlegroups.com. >> >> syzbot will keep track of this bug report. See: >> https://goo.gl/tpsmEJ#status for how to communicate with syzbot. >> syzbot can test patches for this bug, for details see: >> https://goo.gl/tpsmEJ#testing-patches >> > > Note to ULP maintainers > > Probably the code for IPV6_ADDRFORM needs some care if a TCP socket got ULP enabled ? > Maybe simply make sure sk->sk_prot is pristine as in : diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 79fc012dd2cae44b69057c168037b018775d1f49..a72c5c30bc3a55ca65974c537cd089fa4260a8d0 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -183,9 +183,14 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, retv = -EBUSY; break; } - } else if (sk->sk_protocol != IPPROTO_TCP) + } else if (sk->sk_protocol == IPPROTO_TCP) { + if (sk->sk_prot != &tcpv6_prot) { + retv = -EBUSY; + break; + } + } else { break; - + } if (sk->sk_state != TCP_ESTABLISHED) { retv = -ENOTCONN; break; ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: BUG: unable to handle kernel NULL pointer dereference in inet_release 2020-02-25 18:23 ` Eric Dumazet @ 2020-02-26 11:22 ` Jakub Sitnicki 0 siblings, 0 replies; 4+ messages in thread From: Jakub Sitnicki @ 2020-02-26 11:22 UTC (permalink / raw) To: Eric Dumazet Cc: syzbot, andriin, ast, bpf, daniel, davem, kafai, kuba, kuznet, linux-kernel, netdev, songliubraving, syzkaller-bugs, yhs On Tue, Feb 25, 2020 at 07:23 PM CET, Eric Dumazet wrote: > On 2/25/20 12:15 AM, Eric Dumazet wrote: >> >> >> On 2/25/20 12:08 AM, syzbot wrote: >>> Hello, >>> >>> syzbot found the following crash on: >>> >>> HEAD commit: 54dedb5b Merge tag 'for-linus-5.6-rc3-tag' of git://git.ke.. >>> git tree: upstream >>> console output: https://syzkaller.appspot.com/x/log.txt?x=168f7de9e00000 >>> kernel config: https://syzkaller.appspot.com/x/.config?x=3e57a6b450fb9883 >>> dashboard link: https://syzkaller.appspot.com/bug?extid=1938db17e275e85dc328 >>> compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) >>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1681fe09e00000 >>> >>> IMPORTANT: if you fix the bug, please add the following tag to the commit: >>> Reported-by: syzbot+1938db17e275e85dc328@syzkaller.appspotmail.com >>> >>> BUG: kernel NULL pointer dereference, address: 0000000000000000 >>> #PF: supervisor instruction fetch in kernel mode >>> #PF: error_code(0x0010) - not-present page >>> PGD a0113067 P4D a0113067 PUD a8771067 PMD 0 >>> Oops: 0010 [#1] PREEMPT SMP KASAN >>> CPU: 0 PID: 10686 Comm: syz-executor.0 Not tainted 5.6.0-rc2-syzkaller #0 >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >>> RIP: 0010:0x0 >>> Code: Bad RIP value. >>> RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246 >>> RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000 >>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40 >>> RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5 >>> R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098 >>> R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000 >>> FS: 00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0 >>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >>> Call Trace: >>> inet_release+0x165/0x1c0 net/ipv4/af_inet.c:427 >>> __sock_release net/socket.c:605 [inline] >>> sock_close+0xe1/0x260 net/socket.c:1283 >>> __fput+0x2e4/0x740 fs/file_table.c:280 >>> ____fput+0x15/0x20 fs/file_table.c:313 >>> task_work_run+0x176/0x1b0 kernel/task_work.c:113 >>> tracehook_notify_resume include/linux/tracehook.h:188 [inline] >>> exit_to_usermode_loop arch/x86/entry/common.c:164 [inline] >>> prepare_exit_to_usermode+0x480/0x5b0 arch/x86/entry/common.c:195 >>> syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278 >>> do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304 >>> entry_SYSCALL_64_after_hwframe+0x49/0xbe >>> RIP: 0033:0x45c429 >>> Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 >>> RSP: 002b:00007f2ae75dac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 >>> RAX: 0000000000000000 RBX: 00007f2ae75db6d4 RCX: 000000000045c429 >>> RDX: 0000000000000001 RSI: 000000000000011a RDI: 0000000000000004 >>> RBP: 000000000076bf20 R08: 0000000000000038 R09: 0000000000000000 >>> R10: 0000000020000180 R11: 0000000000000246 R12: 00000000ffffffff >>> R13: 0000000000000a9d R14: 00000000004ccfb4 R15: 000000000076bf2c >>> Modules linked in: >>> CR2: 0000000000000000 >>> ---[ end trace 82567b5207e87bae ]--- >>> RIP: 0010:0x0 >>> Code: Bad RIP value. >>> RSP: 0018:ffffc9000281fce0 EFLAGS: 00010246 >>> RAX: 1ffffffff15f48ac RBX: ffffffff8afa4560 RCX: dffffc0000000000 >>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880a69a8f40 >>> RBP: ffffc9000281fd10 R08: ffffffff86ed9b0c R09: ffffed1014d351f5 >>> R10: ffffed1014d351f5 R11: 0000000000000000 R12: ffff8880920d3098 >>> R13: 1ffff1101241a613 R14: ffff8880a69a8f40 R15: 0000000000000000 >>> FS: 00007f2ae75db700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> CR2: ffffffffffffffd6 CR3: 00000000a3b85000 CR4: 00000000001406f0 >>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >>> >>> >>> --- >>> This bug is generated by a bot. It may contain errors. >>> See https://goo.gl/tpsmEJ for more information about syzbot. >>> syzbot engineers can be reached at syzkaller@googlegroups.com. >>> >>> syzbot will keep track of this bug report. See: >>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot. >>> syzbot can test patches for this bug, for details see: >>> https://goo.gl/tpsmEJ#testing-patches >>> >> >> Note to ULP maintainers >> >> Probably the code for IPV6_ADDRFORM needs some care if a TCP socket got ULP enabled ? >> > > Maybe simply make sure sk->sk_prot is pristine as in : > > diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c > index 79fc012dd2cae44b69057c168037b018775d1f49..a72c5c30bc3a55ca65974c537cd089fa4260a8d0 100644 > --- a/net/ipv6/ipv6_sockglue.c > +++ b/net/ipv6/ipv6_sockglue.c > @@ -183,9 +183,14 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, > retv = -EBUSY; > break; > } > - } else if (sk->sk_protocol != IPPROTO_TCP) > + } else if (sk->sk_protocol == IPPROTO_TCP) { > + if (sk->sk_prot != &tcpv6_prot) { > + retv = -EBUSY; > + break; > + } > + } else { > break; > - > + } > if (sk->sk_state != TCP_ESTABLISHED) { > retv = -ENOTCONN; > break; This is a weird one. Only way I can see that syzbot could have triggered a NULL deref on sk->sk_prot->close() at net/ipv4/af_inet.c:427 is if we set sk->sk_prot to a set of kTLS callbacks that were not initialized. That is: 1) setsockopt(fd, SOL_TCP, TCP_ULP, "tls") builds a set kTLS callbacks for AF_INET6 by initializing tls_prots[TLSV6], 2) setsockopt(fd, SOL_IPV6, IPV6_ADDRFORM) changes sk->sk_family to AF_INET, 3) setsockopt(fd, SOL_TLS, TLS_TX, ...) sets sk->sk_prot to uninitialized &tls_prots[TLSV4] based on sk->sk_family. But this could not have happened because setsockopt(IPV6_ADDRFORM) resets sk->sk_prot to &tcp_prot, so tls_setsockopt no longer gets called and attempt to setsockopt(fd, SOL_TLS, TLS_TX) will fail with -ENOPROTOOPT. Also, we hold the sk_lock while setting both IPV6_ADDRFORM and TLX_TX options. Nevertheless, failing IPV6_ADDRFORM with -EBUSY when sk_prot is overwritten sounds like the right thing to do. It looks like a bug that we are not doing it ATM, the crash report aside, because after setsockopt(IPV6_ADDRFORM) icsk_ulp_data remains pointing to a kTLS context, while proto and socket ops get reset to TCPv4 defaults. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-02-26 11:22 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-02-25 8:08 BUG: unable to handle kernel NULL pointer dereference in inet_release syzbot 2020-02-25 8:15 ` Eric Dumazet 2020-02-25 18:23 ` Eric Dumazet 2020-02-26 11:22 ` Jakub Sitnicki
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