* lsipc(1) triggers general protection fault in sysvipc_shm_proc_show() on v4.13-rc2+
@ 2017-07-30 10:10 Dominik Brodowski
2017-07-30 16:28 ` Kees Cook
0 siblings, 1 reply; 6+ messages in thread
From: Dominik Brodowski @ 2017-07-30 10:10 UTC (permalink / raw)
To: keescook, manfred; +Cc: linux-kernel
[-- Attachment #1: Type: text/plain, Size: 2790 bytes --]
Kees, Manfred,
on Linus' most recent kernel (v4.13-rc2+, git head 0a07b238e5f48), lsipc(1)
works as expected in initramfs and before gnome starts up. Afterwards,
running lsipc as user(!) results in the following general protection fault
and a quite unusable system:
[ 183.018415] general protection fault: 0000 [#1] PREEMPT SMP
[ 183.018486] Modules linked in:
[ 183.018521] CPU: 2 PID: 1964 Comm: lsipc Not tainted 4.13.0-rc2+ #2
[ 183.018575] Hardware name: Dell Inc. XPS 13 9343/0TM99H, BIOS A11 12/08/2016
[ 183.018636] task: ffff9f0651708000 task.stack: ffffa8d3837d0000
[ 183.018692] RIP: 0010:shm_add_rss_swap.isra.1+0x13/0xa0
[ 183.018738] RSP: 0018:ffffa8d3837d3d78 EFLAGS: 00010246
[ 183.018785] RAX: 6b6b6b6b6b6b6b6b RBX: ffff9f065c29cc70 RCX: 0000000000000000
[ 183.018845] RDX: ffffa8d3837d3de0 RSI: ffffa8d3837d3dd8 RDI: ffff9f065c29cd50
[ 183.018905] RBP: ffffa8d3837d3d98 R08: 0000000000000000 R09: ffff9f065c29cc70
[ 183.018965] R10: 0000000000000040 R11: 0000000000000000 R12: ffffffff8bc5b9a0
[ 183.019026] R13: ffff9f063838a280 R14: ffff9f065c29cc70 R15: ffff9f068bcecaa0
[ 183.019088] FS: 00007cec9dce2700(0000) GS:ffff9f069f500000(0000) knlGS:0000000000000000
[ 183.019156] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 183.019206] CR2: 00007ffe4e7a8ff8 CR3: 000000020b9ca000 CR4: 00000000003406e0
[ 183.019265] Call Trace:
[ 183.019294] sysvipc_shm_proc_show+0x5e/0x150
[ 183.019338] ? _raw_spin_lock+0x17/0x40
[ 183.019376] ? sysvipc_find_ipc+0xbc/0xf0
[ 183.019416] sysvipc_proc_show+0x1a/0x30
[ 183.019456] seq_read+0x2e9/0x3f0
[ 183.019492] proc_reg_read+0x42/0x70
[ 183.019528] __vfs_read+0x18/0x40
[ 183.019562] vfs_read+0x8e/0x110
[ 183.019595] SyS_read+0x55/0xc0
[ 183.019629] entry_SYSCALL_64_fastpath+0x18/0xa8
[ 183.019671] RIP: 0033:0x7cec9d5fcb90
[ 183.019703] RSP: 002b:00007ffe4e7a97d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 183.019769] RAX: ffffffffffffffda RBX: 000007e254b1a221 RCX: 00007cec9d5fcb90
[ 183.019829] RDX: 0000000000000400 RSI: 000007e255712020 RDI: 0000000000000003
[ 183.019890] RBP: 00007cec9d8ba588 R08: 0000000000000003 R09: 000000000000007c
[ 183.019950] R10: 0000000000000040 R11: 0000000000000246 R12: 00007cec9d8b9820
[ 183.020010] R13: 0000000000000011 R14: 00007ffe4e7a95b0 R15: 00007ffe4e7a95b0
[ 183.020071] Code: 7f 18 48 89 e5 e8 5e ff ff ff 85 c0 75 02 5d c3 0f ff 5d c3 0f 1f 40 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 48 8b 07 <4c> 8b 60 08 48 8b 40 68 48 3d 80 13 47 8b 74 08 48 3d 00 15 45
[ 183.020290] RIP: shm_add_rss_swap.isra.1+0x13/0xa0 RSP: ffffa8d3837d3d78
[ 183.042734] ---[ end trace c5a8076d8f19909f ]---
[ 183.042740] note: lsipc[1964] exited with preempt_count 1
Thanks,
Dominik
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lsipc(1) triggers general protection fault in sysvipc_shm_proc_show() on v4.13-rc2+
2017-07-30 10:10 lsipc(1) triggers general protection fault in sysvipc_shm_proc_show() on v4.13-rc2+ Dominik Brodowski
@ 2017-07-30 16:28 ` Kees Cook
2017-07-30 17:47 ` Kees Cook
0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2017-07-30 16:28 UTC (permalink / raw)
To: Dominik Brodowski; +Cc: Manfred Spraul, LKML
On Sun, Jul 30, 2017 at 3:10 AM, Dominik Brodowski
<linux@dominikbrodowski.net> wrote:
> Kees, Manfred,
>
> on Linus' most recent kernel (v4.13-rc2+, git head 0a07b238e5f48), lsipc(1)
> works as expected in initramfs and before gnome starts up. Afterwards,
> running lsipc as user(!) results in the following general protection fault
> and a quite unusable system:
>
> [ 183.018415] general protection fault: 0000 [#1] PREEMPT SMP
> [ 183.018486] Modules linked in:
> [ 183.018521] CPU: 2 PID: 1964 Comm: lsipc Not tainted 4.13.0-rc2+ #2
> [ 183.018575] Hardware name: Dell Inc. XPS 13 9343/0TM99H, BIOS A11 12/08/2016
> [ 183.018636] task: ffff9f0651708000 task.stack: ffffa8d3837d0000
> [ 183.018692] RIP: 0010:shm_add_rss_swap.isra.1+0x13/0xa0
> [ 183.018738] RSP: 0018:ffffa8d3837d3d78 EFLAGS: 00010246
> [ 183.018785] RAX: 6b6b6b6b6b6b6b6b RBX: ffff9f065c29cc70 RCX: 0000000000000000
> [ 183.018845] RDX: ffffa8d3837d3de0 RSI: ffffa8d3837d3dd8 RDI: ffff9f065c29cd50
> [ 183.018905] RBP: ffffa8d3837d3d98 R08: 0000000000000000 R09: ffff9f065c29cc70
> [ 183.018965] R10: 0000000000000040 R11: 0000000000000000 R12: ffffffff8bc5b9a0
> [ 183.019026] R13: ffff9f063838a280 R14: ffff9f065c29cc70 R15: ffff9f068bcecaa0
> [ 183.019088] FS: 00007cec9dce2700(0000) GS:ffff9f069f500000(0000) knlGS:0000000000000000
> [ 183.019156] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 183.019206] CR2: 00007ffe4e7a8ff8 CR3: 000000020b9ca000 CR4: 00000000003406e0
> [ 183.019265] Call Trace:
> [ 183.019294] sysvipc_shm_proc_show+0x5e/0x150
> [ 183.019338] ? _raw_spin_lock+0x17/0x40
> [ 183.019376] ? sysvipc_find_ipc+0xbc/0xf0
> [ 183.019416] sysvipc_proc_show+0x1a/0x30
> [ 183.019456] seq_read+0x2e9/0x3f0
> [ 183.019492] proc_reg_read+0x42/0x70
> [ 183.019528] __vfs_read+0x18/0x40
> [ 183.019562] vfs_read+0x8e/0x110
> [ 183.019595] SyS_read+0x55/0xc0
> [ 183.019629] entry_SYSCALL_64_fastpath+0x18/0xa8
> [ 183.019671] RIP: 0033:0x7cec9d5fcb90
> [ 183.019703] RSP: 002b:00007ffe4e7a97d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> [ 183.019769] RAX: ffffffffffffffda RBX: 000007e254b1a221 RCX: 00007cec9d5fcb90
> [ 183.019829] RDX: 0000000000000400 RSI: 000007e255712020 RDI: 0000000000000003
> [ 183.019890] RBP: 00007cec9d8ba588 R08: 0000000000000003 R09: 000000000000007c
> [ 183.019950] R10: 0000000000000040 R11: 0000000000000246 R12: 00007cec9d8b9820
> [ 183.020010] R13: 0000000000000011 R14: 00007ffe4e7a95b0 R15: 00007ffe4e7a95b0
> [ 183.020071] Code: 7f 18 48 89 e5 e8 5e ff ff ff 85 c0 75 02 5d c3 0f ff 5d c3 0f 1f 40 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 48 8b 07 <4c> 8b 60 08 48 8b 40 68 48 3d 80 13 47 8b 74 08 48 3d 00 15 45
> [ 183.020290] RIP: shm_add_rss_swap.isra.1+0x13/0xa0 RSP: ffffa8d3837d3d78
> [ 183.042734] ---[ end trace c5a8076d8f19909f ]---
> [ 183.042740] note: lsipc[1964] exited with preempt_count 1
Can you send your config? Also, are you able to do a bisect to find
the specific commit that is triggering this? Are there any interesting
dmesg lines before the general protection fault line?
Thanks!
-Kees
--
Kees Cook
Pixel Security
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lsipc(1) triggers general protection fault in sysvipc_shm_proc_show() on v4.13-rc2+
2017-07-30 16:28 ` Kees Cook
@ 2017-07-30 17:47 ` Kees Cook
2017-07-30 20:16 ` Dominik Brodowski
0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2017-07-30 17:47 UTC (permalink / raw)
To: Dominik Brodowski; +Cc: Manfred Spraul, LKML
On Sun, Jul 30, 2017 at 9:28 AM, Kees Cook <keescook@chromium.org> wrote:
> On Sun, Jul 30, 2017 at 3:10 AM, Dominik Brodowski
> <linux@dominikbrodowski.net> wrote:
>> Kees, Manfred,
>>
>> on Linus' most recent kernel (v4.13-rc2+, git head 0a07b238e5f48), lsipc(1)
>> works as expected in initramfs and before gnome starts up. Afterwards,
>> running lsipc as user(!) results in the following general protection fault
>> and a quite unusable system:
>>
>> [ 183.018415] general protection fault: 0000 [#1] PREEMPT SMP
>> [ 183.018486] Modules linked in:
>> [ 183.018521] CPU: 2 PID: 1964 Comm: lsipc Not tainted 4.13.0-rc2+ #2
>> [ 183.018575] Hardware name: Dell Inc. XPS 13 9343/0TM99H, BIOS A11 12/08/2016
>> [ 183.018636] task: ffff9f0651708000 task.stack: ffffa8d3837d0000
>> [ 183.018692] RIP: 0010:shm_add_rss_swap.isra.1+0x13/0xa0
>> [ 183.018738] RSP: 0018:ffffa8d3837d3d78 EFLAGS: 00010246
>> [ 183.018785] RAX: 6b6b6b6b6b6b6b6b RBX: ffff9f065c29cc70 RCX: 0000000000000000
>> [ 183.018845] RDX: ffffa8d3837d3de0 RSI: ffffa8d3837d3dd8 RDI: ffff9f065c29cd50
>> [ 183.018905] RBP: ffffa8d3837d3d98 R08: 0000000000000000 R09: ffff9f065c29cc70
>> [ 183.018965] R10: 0000000000000040 R11: 0000000000000000 R12: ffffffff8bc5b9a0
>> [ 183.019026] R13: ffff9f063838a280 R14: ffff9f065c29cc70 R15: ffff9f068bcecaa0
>> [ 183.019088] FS: 00007cec9dce2700(0000) GS:ffff9f069f500000(0000) knlGS:0000000000000000
>> [ 183.019156] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 183.019206] CR2: 00007ffe4e7a8ff8 CR3: 000000020b9ca000 CR4: 00000000003406e0
>> [ 183.019265] Call Trace:
>> [ 183.019294] sysvipc_shm_proc_show+0x5e/0x150
>> [ 183.019338] ? _raw_spin_lock+0x17/0x40
>> [ 183.019376] ? sysvipc_find_ipc+0xbc/0xf0
>> [ 183.019416] sysvipc_proc_show+0x1a/0x30
>> [ 183.019456] seq_read+0x2e9/0x3f0
>> [ 183.019492] proc_reg_read+0x42/0x70
>> [ 183.019528] __vfs_read+0x18/0x40
>> [ 183.019562] vfs_read+0x8e/0x110
>> [ 183.019595] SyS_read+0x55/0xc0
>> [ 183.019629] entry_SYSCALL_64_fastpath+0x18/0xa8
>> [ 183.019671] RIP: 0033:0x7cec9d5fcb90
>> [ 183.019703] RSP: 002b:00007ffe4e7a97d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
>> [ 183.019769] RAX: ffffffffffffffda RBX: 000007e254b1a221 RCX: 00007cec9d5fcb90
>> [ 183.019829] RDX: 0000000000000400 RSI: 000007e255712020 RDI: 0000000000000003
>> [ 183.019890] RBP: 00007cec9d8ba588 R08: 0000000000000003 R09: 000000000000007c
>> [ 183.019950] R10: 0000000000000040 R11: 0000000000000246 R12: 00007cec9d8b9820
>> [ 183.020010] R13: 0000000000000011 R14: 00007ffe4e7a95b0 R15: 00007ffe4e7a95b0
>> [ 183.020071] Code: 7f 18 48 89 e5 e8 5e ff ff ff 85 c0 75 02 5d c3 0f ff 5d c3 0f 1f 40 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 48 8b 07 <4c> 8b 60 08 48 8b 40 68 48 3d 80 13 47 8b 74 08 48 3d 00 15 45
>> [ 183.020290] RIP: shm_add_rss_swap.isra.1+0x13/0xa0 RSP: ffffa8d3837d3d78
>> [ 183.042734] ---[ end trace c5a8076d8f19909f ]---
>> [ 183.042740] note: lsipc[1964] exited with preempt_count 1
>
> Can you send your config? Also, are you able to do a bisect to find
> the specific commit that is triggering this? Are there any interesting
> dmesg lines before the general protection fault line?
Ah, I have been able to reproduce this now. I'll see if I can track this down...
[ 20.640404] BUG: unable to handle kernel NULL pointer dereference
at 0000000000000088
-Kees
--
Kees Cook
Pixel Security
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lsipc(1) triggers general protection fault in sysvipc_shm_proc_show() on v4.13-rc2+
2017-07-30 17:47 ` Kees Cook
@ 2017-07-30 20:16 ` Dominik Brodowski
2017-07-30 20:36 ` Kees Cook
0 siblings, 1 reply; 6+ messages in thread
From: Dominik Brodowski @ 2017-07-30 20:16 UTC (permalink / raw)
To: Kees Cook; +Cc: Manfred Spraul, LKML
Kees,
thanks for taking a look at this!
On Sun, Jul 30, 2017 at 10:47:21AM -0700, Kees Cook wrote:
> On Sun, Jul 30, 2017 at 9:28 AM, Kees Cook <keescook@chromium.org> wrote:
> > On Sun, Jul 30, 2017 at 3:10 AM, Dominik Brodowski
> > <linux@dominikbrodowski.net> wrote:
> >> Kees, Manfred,
> >>
> >> on Linus' most recent kernel (v4.13-rc2+, git head 0a07b238e5f48), lsipc(1)
> >> works as expected in initramfs and before gnome starts up. Afterwards,
> >> running lsipc as user(!) results in the following general protection fault
> >> and a quite unusable system:
> >>
> >> [ 183.018415] general protection fault: 0000 [#1] PREEMPT SMP
> >> [ 183.018486] Modules linked in:
> >> [ 183.018521] CPU: 2 PID: 1964 Comm: lsipc Not tainted 4.13.0-rc2+ #2
> >> [ 183.018575] Hardware name: Dell Inc. XPS 13 9343/0TM99H, BIOS A11 12/08/2016
> >> [ 183.018636] task: ffff9f0651708000 task.stack: ffffa8d3837d0000
> >> [ 183.018692] RIP: 0010:shm_add_rss_swap.isra.1+0x13/0xa0
> >> [ 183.018738] RSP: 0018:ffffa8d3837d3d78 EFLAGS: 00010246
> >> [ 183.018785] RAX: 6b6b6b6b6b6b6b6b RBX: ffff9f065c29cc70 RCX: 0000000000000000
> >> [ 183.018845] RDX: ffffa8d3837d3de0 RSI: ffffa8d3837d3dd8 RDI: ffff9f065c29cd50
> >> [ 183.018905] RBP: ffffa8d3837d3d98 R08: 0000000000000000 R09: ffff9f065c29cc70
> >> [ 183.018965] R10: 0000000000000040 R11: 0000000000000000 R12: ffffffff8bc5b9a0
> >> [ 183.019026] R13: ffff9f063838a280 R14: ffff9f065c29cc70 R15: ffff9f068bcecaa0
> >> [ 183.019088] FS: 00007cec9dce2700(0000) GS:ffff9f069f500000(0000) knlGS:0000000000000000
> >> [ 183.019156] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> >> [ 183.019206] CR2: 00007ffe4e7a8ff8 CR3: 000000020b9ca000 CR4: 00000000003406e0
> >> [ 183.019265] Call Trace:
> >> [ 183.019294] sysvipc_shm_proc_show+0x5e/0x150
> >> [ 183.019338] ? _raw_spin_lock+0x17/0x40
> >> [ 183.019376] ? sysvipc_find_ipc+0xbc/0xf0
> >> [ 183.019416] sysvipc_proc_show+0x1a/0x30
> >> [ 183.019456] seq_read+0x2e9/0x3f0
> >> [ 183.019492] proc_reg_read+0x42/0x70
> >> [ 183.019528] __vfs_read+0x18/0x40
> >> [ 183.019562] vfs_read+0x8e/0x110
> >> [ 183.019595] SyS_read+0x55/0xc0
> >> [ 183.019629] entry_SYSCALL_64_fastpath+0x18/0xa8
> >> [ 183.019671] RIP: 0033:0x7cec9d5fcb90
> >> [ 183.019703] RSP: 002b:00007ffe4e7a97d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> >> [ 183.019769] RAX: ffffffffffffffda RBX: 000007e254b1a221 RCX: 00007cec9d5fcb90
> >> [ 183.019829] RDX: 0000000000000400 RSI: 000007e255712020 RDI: 0000000000000003
> >> [ 183.019890] RBP: 00007cec9d8ba588 R08: 0000000000000003 R09: 000000000000007c
> >> [ 183.019950] R10: 0000000000000040 R11: 0000000000000246 R12: 00007cec9d8b9820
> >> [ 183.020010] R13: 0000000000000011 R14: 00007ffe4e7a95b0 R15: 00007ffe4e7a95b0
> >> [ 183.020071] Code: 7f 18 48 89 e5 e8 5e ff ff ff 85 c0 75 02 5d c3 0f ff 5d c3 0f 1f 40 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 48 8b 07 <4c> 8b 60 08 48 8b 40 68 48 3d 80 13 47 8b 74 08 48 3d 00 15 45
> >> [ 183.020290] RIP: shm_add_rss_swap.isra.1+0x13/0xa0 RSP: ffffa8d3837d3d78
> >> [ 183.042734] ---[ end trace c5a8076d8f19909f ]---
> >> [ 183.042740] note: lsipc[1964] exited with preempt_count 1
> >
> > Can you send your config? Also, are you able to do a bisect to find
> > the specific commit that is triggering this? Are there any interesting
> > dmesg lines before the general protection fault line?
>
> Ah, I have been able to reproduce this now. I'll see if I can track this down...
>
> [ 20.640404] BUG: unable to handle kernel NULL pointer dereference
> at 0000000000000088
I've bisected it to between v4.13-rc1 and 96080f697786 so far, ~7 more
kernels/reboots to go. That leaves no code changes to ipc/, but some
randstruct changes ( I have set CONFIG_GCC_PLUGIN_RANDSTRUCT=y ) which
touch some ipc-related code.
And since you asked: When I triggered the general protection fault, no
NULL pointer message or other notable line was printed out in dmesg.
When testing 96080f697786, I triggered a NULL pointer as well, but no
general protection fault.
Best,
Dominik
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lsipc(1) triggers general protection fault in sysvipc_shm_proc_show() on v4.13-rc2+
2017-07-30 20:16 ` Dominik Brodowski
@ 2017-07-30 20:36 ` Kees Cook
2017-07-30 21:06 ` Dominik Brodowski
0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2017-07-30 20:36 UTC (permalink / raw)
To: Dominik Brodowski; +Cc: Manfred Spraul, LKML
On Sun, Jul 30, 2017 at 1:16 PM, Dominik Brodowski
<linux@dominikbrodowski.net> wrote:
> I've bisected it to between v4.13-rc1 and 96080f697786 so far, ~7 more
> kernels/reboots to go. That leaves no code changes to ipc/, but some
> randstruct changes ( I have set CONFIG_GCC_PLUGIN_RANDSTRUCT=y ) which
> touch some ipc-related code.
Excellent, thanks; I bisected this as well. There was a missing
container_of() in the proc handler. I've sent a patch for this now.
Thanks for the report!
-Kees
--
Kees Cook
Pixel Security
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lsipc(1) triggers general protection fault in sysvipc_shm_proc_show() on v4.13-rc2+
2017-07-30 20:36 ` Kees Cook
@ 2017-07-30 21:06 ` Dominik Brodowski
0 siblings, 0 replies; 6+ messages in thread
From: Dominik Brodowski @ 2017-07-30 21:06 UTC (permalink / raw)
To: Kees Cook; +Cc: Manfred Spraul, LKML
[-- Attachment #1: Type: text/plain, Size: 737 bytes --]
On Sun, Jul 30, 2017 at 01:36:51PM -0700, Kees Cook wrote:
> On Sun, Jul 30, 2017 at 1:16 PM, Dominik Brodowski
> <linux@dominikbrodowski.net> wrote:
> > I've bisected it to between v4.13-rc1 and 96080f697786 so far, ~7 more
> > kernels/reboots to go. That leaves no code changes to ipc/, but some
> > randstruct changes ( I have set CONFIG_GCC_PLUGIN_RANDSTRUCT=y ) which
> > touch some ipc-related code.
>
> Excellent, thanks; I bisected this as well. There was a missing
> container_of() in the proc handler. I've sent a patch for this now.
> Thanks for the report!
Thank you for fixing this issue - I can confirm that your patch (v2), on top
of v4.13-rc3, fixes the issue I've been seeing.
Thanks again,
Dominik
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^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-07-30 21:07 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-07-30 10:10 lsipc(1) triggers general protection fault in sysvipc_shm_proc_show() on v4.13-rc2+ Dominik Brodowski
2017-07-30 16:28 ` Kees Cook
2017-07-30 17:47 ` Kees Cook
2017-07-30 20:16 ` Dominik Brodowski
2017-07-30 20:36 ` Kees Cook
2017-07-30 21:06 ` Dominik Brodowski
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