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[SRU,Groovy,Hirsute,Impish] UBUNTU: ubuntu-host: add generic lseek op

Message ID 20210630091408.10053-1-colin.king@canonical.com
State New
Headers show
Series [SRU,Groovy,Hirsute,Impish] UBUNTU: ubuntu-host: add generic lseek op | expand

Commit Message

Colin Ian King June 30, 2021, 9:14 a.m. UTC 
From: Colin Ian King <colin.king@canonical.com>

BugLink: https://bugs.launchpad.net/1934110

Currently the lseek op is null and seeking on the esm-token procfs
file will cause an oops as detected by the stress-ng procfs stressor
as shown by the following splat:

[  942.470568] BUG: kernel NULL pointer dereference, address: 0000000000000000
[  942.471157] #PF: supervisor instruction fetch in kernel mode
[  942.471724] #PF: error_code(0x0010) - not-present page
[  942.472297] PGD 0 P4D 0
[  942.472867] Oops: 0010 [#1] SMP PTI
[  942.473435] CPU: 2 PID: 5661 Comm: stress-ng Not tainted 5.13.0-9-generic #9
[  942.474012] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
[  942.474599] RIP: 0010:0x0
[  942.475194] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
[  942.475792] RSP: 0018:ffffaacf80ff7eb8 EFLAGS: 00010246
[  942.476383] RAX: 0000000000000000 RBX: ffff9eaa8a175240 RCX: 0000000000000001
[  942.476986] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9eaa838d5800
[  942.477600] RBP: ffffaacf80ff7ed0 R08: 0000000000004000 R09: 0000000000000004
[  942.478203] R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
[  942.478800] R13: 0000000000000000 R14: ffffffffffffffea R15: ffff9eaa838d5800
[  942.479399] FS:  00007f998d487f00(0000) GS:ffff9eaaffc80000(0000) knlGS:0000000000000000
[  942.480006] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  942.480607] CR2: ffffffffffffffd6 CR3: 000000010a774002 CR4: 0000000000370ee0
[  942.481219] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  942.481855] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  942.482458] Call Trace:
[  942.483052]  proc_reg_llseek+0x4e/0x80
[  942.483646]  ? __fdget_pos+0x43/0x50
[  942.484234]  ksys_lseek+0x84/0xc0
[  942.484815]  __x64_sys_lseek+0x1a/0x20
[  942.485412]  do_syscall_64+0x61/0xb0
[  942.485966]  ? asm_exc_page_fault+0x8/0x30
[  942.486476]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  942.486994] RIP: 0033:0x7f998d5c1cdb
[  942.487512] Code: ff ff c3 0f 1f 40 00 48 8b 15 89 81 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb ba 0f 1f 00 f3 0f 1e fa b8 08 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 59 81 0d 00 f7 d8
[  942.488593] RSP: 002b:00007ffdf61c5328 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
[  942.489148] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f998d5c1cdb
[  942.489710] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
[  942.490252] RBP: 0000000000000004 R08: 000001785e4740dd R09: 0000562dbebb9e50
[  942.490801] R10: 00007ffdf61c5300 R11: 0000000000000246 R12: 00007ffdf61c63f0
[  942.491354] R13: 00007ffdf61c53f0 R14: 0000000000000003 R15: 00000000000001e9

Fix this by using the generic lseek operation.

Fixes: 71adefd254f2 ("UBUNTU: Add ubuntu-host module")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 ubuntu/ubuntu-host/ubuntu-host.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Colin Ian King June 30, 2021, 9:16 a.m. UTC | #1 
On 30/06/2021 10:14, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> BugLink: https://bugs.launchpad.net/1934110

Bah, that should be:

BugLink: https://bugs.launchpad.net/bugs/1934110

..can that be fixed up when it is applied, or shall I send a V2?

> 
> Currently the lseek op is null and seeking on the esm-token procfs
> file will cause an oops as detected by the stress-ng procfs stressor
> as shown by the following splat:
> 
> [  942.470568] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [  942.471157] #PF: supervisor instruction fetch in kernel mode
> [  942.471724] #PF: error_code(0x0010) - not-present page
> [  942.472297] PGD 0 P4D 0
> [  942.472867] Oops: 0010 [#1] SMP PTI
> [  942.473435] CPU: 2 PID: 5661 Comm: stress-ng Not tainted 5.13.0-9-generic #9
> [  942.474012] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
> [  942.474599] RIP: 0010:0x0
> [  942.475194] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
> [  942.475792] RSP: 0018:ffffaacf80ff7eb8 EFLAGS: 00010246
> [  942.476383] RAX: 0000000000000000 RBX: ffff9eaa8a175240 RCX: 0000000000000001
> [  942.476986] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9eaa838d5800
> [  942.477600] RBP: ffffaacf80ff7ed0 R08: 0000000000004000 R09: 0000000000000004
> [  942.478203] R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
> [  942.478800] R13: 0000000000000000 R14: ffffffffffffffea R15: ffff9eaa838d5800
> [  942.479399] FS:  00007f998d487f00(0000) GS:ffff9eaaffc80000(0000) knlGS:0000000000000000
> [  942.480006] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  942.480607] CR2: ffffffffffffffd6 CR3: 000000010a774002 CR4: 0000000000370ee0
> [  942.481219] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [  942.481855] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [  942.482458] Call Trace:
> [  942.483052]  proc_reg_llseek+0x4e/0x80
> [  942.483646]  ? __fdget_pos+0x43/0x50
> [  942.484234]  ksys_lseek+0x84/0xc0
> [  942.484815]  __x64_sys_lseek+0x1a/0x20
> [  942.485412]  do_syscall_64+0x61/0xb0
> [  942.485966]  ? asm_exc_page_fault+0x8/0x30
> [  942.486476]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> [  942.486994] RIP: 0033:0x7f998d5c1cdb
> [  942.487512] Code: ff ff c3 0f 1f 40 00 48 8b 15 89 81 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb ba 0f 1f 00 f3 0f 1e fa b8 08 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 59 81 0d 00 f7 d8
> [  942.488593] RSP: 002b:00007ffdf61c5328 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
> [  942.489148] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f998d5c1cdb
> [  942.489710] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
> [  942.490252] RBP: 0000000000000004 R08: 000001785e4740dd R09: 0000562dbebb9e50
> [  942.490801] R10: 00007ffdf61c5300 R11: 0000000000000246 R12: 00007ffdf61c63f0
> [  942.491354] R13: 00007ffdf61c53f0 R14: 0000000000000003 R15: 00000000000001e9
> 
> Fix this by using the generic lseek operation.
> 
> Fixes: 71adefd254f2 ("UBUNTU: Add ubuntu-host module")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  ubuntu/ubuntu-host/ubuntu-host.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/ubuntu/ubuntu-host/ubuntu-host.c b/ubuntu/ubuntu-host/ubuntu-host.c
> index 1abd402..a4c0636 100644
> --- a/ubuntu/ubuntu-host/ubuntu-host.c
> +++ b/ubuntu/ubuntu-host/ubuntu-host.c
> @@ -38,6 +38,8 @@ static ssize_t esm_token_write(struct file *f, const char __user *buf,
>  static const struct proc_ops esm_token_fops = {
>  	.proc_read = esm_token_read,
>  	.proc_write = esm_token_write,
> +	.proc_lseek = default_llseek,
> +
>  };
>  
>  static void ubuntu_host_cleanup(void)
>
Stefan Bader June 30, 2021, 9:21 a.m. UTC | #2 
On 30.06.21 11:16, Colin Ian King wrote:
> On 30/06/2021 10:14, Colin King wrote:
>> From: Colin Ian King <colin.king@canonical.com>
>>
>> BugLink: https://bugs.launchpad.net/1934110
> 
> Bah, that should be:
> 
> BugLink: https://bugs.launchpad.net/bugs/1934110
> 
> ..can that be fixed up when it is applied, or shall I send a V2?

Can be fixed when applying.
> 
>>
>> Currently the lseek op is null and seeking on the esm-token procfs
>> file will cause an oops as detected by the stress-ng procfs stressor
>> as shown by the following splat:
>>
>> [  942.470568] BUG: kernel NULL pointer dereference, address: 0000000000000000
>> [  942.471157] #PF: supervisor instruction fetch in kernel mode
>> [  942.471724] #PF: error_code(0x0010) - not-present page
>> [  942.472297] PGD 0 P4D 0
>> [  942.472867] Oops: 0010 [#1] SMP PTI
>> [  942.473435] CPU: 2 PID: 5661 Comm: stress-ng Not tainted 5.13.0-9-generic #9
>> [  942.474012] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
>> [  942.474599] RIP: 0010:0x0
>> [  942.475194] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
>> [  942.475792] RSP: 0018:ffffaacf80ff7eb8 EFLAGS: 00010246
>> [  942.476383] RAX: 0000000000000000 RBX: ffff9eaa8a175240 RCX: 0000000000000001
>> [  942.476986] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9eaa838d5800
>> [  942.477600] RBP: ffffaacf80ff7ed0 R08: 0000000000004000 R09: 0000000000000004
>> [  942.478203] R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
>> [  942.478800] R13: 0000000000000000 R14: ffffffffffffffea R15: ffff9eaa838d5800
>> [  942.479399] FS:  00007f998d487f00(0000) GS:ffff9eaaffc80000(0000) knlGS:0000000000000000
>> [  942.480006] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [  942.480607] CR2: ffffffffffffffd6 CR3: 000000010a774002 CR4: 0000000000370ee0
>> [  942.481219] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> [  942.481855] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> [  942.482458] Call Trace:
>> [  942.483052]  proc_reg_llseek+0x4e/0x80
>> [  942.483646]  ? __fdget_pos+0x43/0x50
>> [  942.484234]  ksys_lseek+0x84/0xc0
>> [  942.484815]  __x64_sys_lseek+0x1a/0x20
>> [  942.485412]  do_syscall_64+0x61/0xb0
>> [  942.485966]  ? asm_exc_page_fault+0x8/0x30
>> [  942.486476]  entry_SYSCALL_64_after_hwframe+0x44/0xae
>> [  942.486994] RIP: 0033:0x7f998d5c1cdb
>> [  942.487512] Code: ff ff c3 0f 1f 40 00 48 8b 15 89 81 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb ba 0f 1f 00 f3 0f 1e fa b8 08 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 59 81 0d 00 f7 d8
>> [  942.488593] RSP: 002b:00007ffdf61c5328 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
>> [  942.489148] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f998d5c1cdb
>> [  942.489710] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
>> [  942.490252] RBP: 0000000000000004 R08: 000001785e4740dd R09: 0000562dbebb9e50
>> [  942.490801] R10: 00007ffdf61c5300 R11: 0000000000000246 R12: 00007ffdf61c63f0
>> [  942.491354] R13: 00007ffdf61c53f0 R14: 0000000000000003 R15: 00000000000001e9
>>
>> Fix this by using the generic lseek operation.
>>
>> Fixes: 71adefd254f2 ("UBUNTU: Add ubuntu-host module")
>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
>> ---
>>   ubuntu/ubuntu-host/ubuntu-host.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/ubuntu/ubuntu-host/ubuntu-host.c b/ubuntu/ubuntu-host/ubuntu-host.c
>> index 1abd402..a4c0636 100644
>> --- a/ubuntu/ubuntu-host/ubuntu-host.c
>> +++ b/ubuntu/ubuntu-host/ubuntu-host.c
>> @@ -38,6 +38,8 @@ static ssize_t esm_token_write(struct file *f, const char __user *buf,
>>   static const struct proc_ops esm_token_fops = {
>>   	.proc_read = esm_token_read,
>>   	.proc_write = esm_token_write,
>> +	.proc_lseek = default_llseek,
>> +
>>   };
>>   
>>   static void ubuntu_host_cleanup(void)
>>
> 
>
Andrea Righi July 1, 2021, 3:14 p.m. UTC | #3 
On Wed, Jun 30, 2021 at 10:14:08AM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> BugLink: https://bugs.launchpad.net/1934110
> 
> Currently the lseek op is null and seeking on the esm-token procfs
> file will cause an oops as detected by the stress-ng procfs stressor
> as shown by the following splat:
> 
> [  942.470568] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [  942.471157] #PF: supervisor instruction fetch in kernel mode
> [  942.471724] #PF: error_code(0x0010) - not-present page
> [  942.472297] PGD 0 P4D 0
> [  942.472867] Oops: 0010 [#1] SMP PTI
> [  942.473435] CPU: 2 PID: 5661 Comm: stress-ng Not tainted 5.13.0-9-generic #9
> [  942.474012] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
> [  942.474599] RIP: 0010:0x0
> [  942.475194] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
> [  942.475792] RSP: 0018:ffffaacf80ff7eb8 EFLAGS: 00010246
> [  942.476383] RAX: 0000000000000000 RBX: ffff9eaa8a175240 RCX: 0000000000000001
> [  942.476986] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9eaa838d5800
> [  942.477600] RBP: ffffaacf80ff7ed0 R08: 0000000000004000 R09: 0000000000000004
> [  942.478203] R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
> [  942.478800] R13: 0000000000000000 R14: ffffffffffffffea R15: ffff9eaa838d5800
> [  942.479399] FS:  00007f998d487f00(0000) GS:ffff9eaaffc80000(0000) knlGS:0000000000000000
> [  942.480006] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  942.480607] CR2: ffffffffffffffd6 CR3: 000000010a774002 CR4: 0000000000370ee0
> [  942.481219] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [  942.481855] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [  942.482458] Call Trace:
> [  942.483052]  proc_reg_llseek+0x4e/0x80
> [  942.483646]  ? __fdget_pos+0x43/0x50
> [  942.484234]  ksys_lseek+0x84/0xc0
> [  942.484815]  __x64_sys_lseek+0x1a/0x20
> [  942.485412]  do_syscall_64+0x61/0xb0
> [  942.485966]  ? asm_exc_page_fault+0x8/0x30
> [  942.486476]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> [  942.486994] RIP: 0033:0x7f998d5c1cdb
> [  942.487512] Code: ff ff c3 0f 1f 40 00 48 8b 15 89 81 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb ba 0f 1f 00 f3 0f 1e fa b8 08 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 59 81 0d 00 f7 d8
> [  942.488593] RSP: 002b:00007ffdf61c5328 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
> [  942.489148] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f998d5c1cdb
> [  942.489710] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
> [  942.490252] RBP: 0000000000000004 R08: 000001785e4740dd R09: 0000562dbebb9e50
> [  942.490801] R10: 00007ffdf61c5300 R11: 0000000000000246 R12: 00007ffdf61c63f0
> [  942.491354] R13: 00007ffdf61c53f0 R14: 0000000000000003 R15: 00000000000001e9
> 
> Fix this by using the generic lseek operation.
> 
> Fixes: 71adefd254f2 ("UBUNTU: Add ubuntu-host module")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Applied to impish, fixing the buglink.

Thanks,
-Andrea
Stefan Bader July 6, 2021, 7:29 a.m. UTC | #4 
On 30.06.21 11:14, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
BugLink: https://bugs.launchpad.net/bugs/1934110
> 
> Currently the lseek op is null and seeking on the esm-token procfs
> file will cause an oops as detected by the stress-ng procfs stressor
> as shown by the following splat:
> 
> [  942.470568] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [  942.471157] #PF: supervisor instruction fetch in kernel mode
> [  942.471724] #PF: error_code(0x0010) - not-present page
> [  942.472297] PGD 0 P4D 0
> [  942.472867] Oops: 0010 [#1] SMP PTI
> [  942.473435] CPU: 2 PID: 5661 Comm: stress-ng Not tainted 5.13.0-9-generic #9
> [  942.474012] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
> [  942.474599] RIP: 0010:0x0
> [  942.475194] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
> [  942.475792] RSP: 0018:ffffaacf80ff7eb8 EFLAGS: 00010246
> [  942.476383] RAX: 0000000000000000 RBX: ffff9eaa8a175240 RCX: 0000000000000001
> [  942.476986] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9eaa838d5800
> [  942.477600] RBP: ffffaacf80ff7ed0 R08: 0000000000004000 R09: 0000000000000004
> [  942.478203] R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
> [  942.478800] R13: 0000000000000000 R14: ffffffffffffffea R15: ffff9eaa838d5800
> [  942.479399] FS:  00007f998d487f00(0000) GS:ffff9eaaffc80000(0000) knlGS:0000000000000000
> [  942.480006] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  942.480607] CR2: ffffffffffffffd6 CR3: 000000010a774002 CR4: 0000000000370ee0
> [  942.481219] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [  942.481855] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [  942.482458] Call Trace:
> [  942.483052]  proc_reg_llseek+0x4e/0x80
> [  942.483646]  ? __fdget_pos+0x43/0x50
> [  942.484234]  ksys_lseek+0x84/0xc0
> [  942.484815]  __x64_sys_lseek+0x1a/0x20
> [  942.485412]  do_syscall_64+0x61/0xb0
> [  942.485966]  ? asm_exc_page_fault+0x8/0x30
> [  942.486476]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> [  942.486994] RIP: 0033:0x7f998d5c1cdb
> [  942.487512] Code: ff ff c3 0f 1f 40 00 48 8b 15 89 81 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb ba 0f 1f 00 f3 0f 1e fa b8 08 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 59 81 0d 00 f7 d8
> [  942.488593] RSP: 002b:00007ffdf61c5328 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
> [  942.489148] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f998d5c1cdb
> [  942.489710] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
> [  942.490252] RBP: 0000000000000004 R08: 000001785e4740dd R09: 0000562dbebb9e50
> [  942.490801] R10: 00007ffdf61c5300 R11: 0000000000000246 R12: 00007ffdf61c63f0
> [  942.491354] R13: 00007ffdf61c53f0 R14: 0000000000000003 R15: 00000000000001e9
> 
> Fix this by using the generic lseek operation.
> 
> Fixes: 71adefd254f2 ("UBUNTU: Add ubuntu-host module")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
> ---

With the adjusted bug reference.

-Stefan

>   ubuntu/ubuntu-host/ubuntu-host.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/ubuntu/ubuntu-host/ubuntu-host.c b/ubuntu/ubuntu-host/ubuntu-host.c
> index 1abd402..a4c0636 100644
> --- a/ubuntu/ubuntu-host/ubuntu-host.c
> +++ b/ubuntu/ubuntu-host/ubuntu-host.c
> @@ -38,6 +38,8 @@ static ssize_t esm_token_write(struct file *f, const char __user *buf,
>   static const struct proc_ops esm_token_fops = {
>   	.proc_read = esm_token_read,
>   	.proc_write = esm_token_write,
> +	.proc_lseek = default_llseek,
> +
>   };
>   
>   static void ubuntu_host_cleanup(void)
>
Tim Gardner July 6, 2021, 1:29 p.m. UTC | #5 
Acked-by: Tim Gardner <tim.gardner@canonical.com>

On 6/30/21 3:14 AM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> BugLink: https://bugs.launchpad.net/1934110
> 
> Currently the lseek op is null and seeking on the esm-token procfs
> file will cause an oops as detected by the stress-ng procfs stressor
> as shown by the following splat:
> 
> [  942.470568] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [  942.471157] #PF: supervisor instruction fetch in kernel mode
> [  942.471724] #PF: error_code(0x0010) - not-present page
> [  942.472297] PGD 0 P4D 0
> [  942.472867] Oops: 0010 [#1] SMP PTI
> [  942.473435] CPU: 2 PID: 5661 Comm: stress-ng Not tainted 5.13.0-9-generic #9
> [  942.474012] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
> [  942.474599] RIP: 0010:0x0
> [  942.475194] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
> [  942.475792] RSP: 0018:ffffaacf80ff7eb8 EFLAGS: 00010246
> [  942.476383] RAX: 0000000000000000 RBX: ffff9eaa8a175240 RCX: 0000000000000001
> [  942.476986] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9eaa838d5800
> [  942.477600] RBP: ffffaacf80ff7ed0 R08: 0000000000004000 R09: 0000000000000004
> [  942.478203] R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
> [  942.478800] R13: 0000000000000000 R14: ffffffffffffffea R15: ffff9eaa838d5800
> [  942.479399] FS:  00007f998d487f00(0000) GS:ffff9eaaffc80000(0000) knlGS:0000000000000000
> [  942.480006] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  942.480607] CR2: ffffffffffffffd6 CR3: 000000010a774002 CR4: 0000000000370ee0
> [  942.481219] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [  942.481855] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [  942.482458] Call Trace:
> [  942.483052]  proc_reg_llseek+0x4e/0x80
> [  942.483646]  ? __fdget_pos+0x43/0x50
> [  942.484234]  ksys_lseek+0x84/0xc0
> [  942.484815]  __x64_sys_lseek+0x1a/0x20
> [  942.485412]  do_syscall_64+0x61/0xb0
> [  942.485966]  ? asm_exc_page_fault+0x8/0x30
> [  942.486476]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> [  942.486994] RIP: 0033:0x7f998d5c1cdb
> [  942.487512] Code: ff ff c3 0f 1f 40 00 48 8b 15 89 81 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb ba 0f 1f 00 f3 0f 1e fa b8 08 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 59 81 0d 00 f7 d8
> [  942.488593] RSP: 002b:00007ffdf61c5328 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
> [  942.489148] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f998d5c1cdb
> [  942.489710] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
> [  942.490252] RBP: 0000000000000004 R08: 000001785e4740dd R09: 0000562dbebb9e50
> [  942.490801] R10: 00007ffdf61c5300 R11: 0000000000000246 R12: 00007ffdf61c63f0
> [  942.491354] R13: 00007ffdf61c53f0 R14: 0000000000000003 R15: 00000000000001e9
> 
> Fix this by using the generic lseek operation.
> 
> Fixes: 71adefd254f2 ("UBUNTU: Add ubuntu-host module")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   ubuntu/ubuntu-host/ubuntu-host.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/ubuntu/ubuntu-host/ubuntu-host.c b/ubuntu/ubuntu-host/ubuntu-host.c
> index 1abd402..a4c0636 100644
> --- a/ubuntu/ubuntu-host/ubuntu-host.c
> +++ b/ubuntu/ubuntu-host/ubuntu-host.c
> @@ -38,6 +38,8 @@ static ssize_t esm_token_write(struct file *f, const char __user *buf,
>   static const struct proc_ops esm_token_fops = {
>   	.proc_read = esm_token_read,
>   	.proc_write = esm_token_write,
> +	.proc_lseek = default_llseek,
> +
>   };
>   
>   static void ubuntu_host_cleanup(void)
>
Kleber Sacilotto de Souza July 15, 2021, 3:43 p.m. UTC | #6 
On 30.06.21 11:14, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> BugLink: https://bugs.launchpad.net/1934110
> 
> Currently the lseek op is null and seeking on the esm-token procfs
> file will cause an oops as detected by the stress-ng procfs stressor
> as shown by the following splat:
> 
> [  942.470568] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [  942.471157] #PF: supervisor instruction fetch in kernel mode
> [  942.471724] #PF: error_code(0x0010) - not-present page
> [  942.472297] PGD 0 P4D 0
> [  942.472867] Oops: 0010 [#1] SMP PTI
> [  942.473435] CPU: 2 PID: 5661 Comm: stress-ng Not tainted 5.13.0-9-generic #9
> [  942.474012] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
> [  942.474599] RIP: 0010:0x0
> [  942.475194] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
> [  942.475792] RSP: 0018:ffffaacf80ff7eb8 EFLAGS: 00010246
> [  942.476383] RAX: 0000000000000000 RBX: ffff9eaa8a175240 RCX: 0000000000000001
> [  942.476986] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9eaa838d5800
> [  942.477600] RBP: ffffaacf80ff7ed0 R08: 0000000000004000 R09: 0000000000000004
> [  942.478203] R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
> [  942.478800] R13: 0000000000000000 R14: ffffffffffffffea R15: ffff9eaa838d5800
> [  942.479399] FS:  00007f998d487f00(0000) GS:ffff9eaaffc80000(0000) knlGS:0000000000000000
> [  942.480006] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  942.480607] CR2: ffffffffffffffd6 CR3: 000000010a774002 CR4: 0000000000370ee0
> [  942.481219] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [  942.481855] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [  942.482458] Call Trace:
> [  942.483052]  proc_reg_llseek+0x4e/0x80
> [  942.483646]  ? __fdget_pos+0x43/0x50
> [  942.484234]  ksys_lseek+0x84/0xc0
> [  942.484815]  __x64_sys_lseek+0x1a/0x20
> [  942.485412]  do_syscall_64+0x61/0xb0
> [  942.485966]  ? asm_exc_page_fault+0x8/0x30
> [  942.486476]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> [  942.486994] RIP: 0033:0x7f998d5c1cdb
> [  942.487512] Code: ff ff c3 0f 1f 40 00 48 8b 15 89 81 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb ba 0f 1f 00 f3 0f 1e fa b8 08 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 59 81 0d 00 f7 d8
> [  942.488593] RSP: 002b:00007ffdf61c5328 EFLAGS: 00000246 ORIG_RAX: 0000000000000008
> [  942.489148] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f998d5c1cdb
> [  942.489710] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
> [  942.490252] RBP: 0000000000000004 R08: 000001785e4740dd R09: 0000562dbebb9e50
> [  942.490801] R10: 00007ffdf61c5300 R11: 0000000000000246 R12: 00007ffdf61c63f0
> [  942.491354] R13: 00007ffdf61c53f0 R14: 0000000000000003 R15: 00000000000001e9
> 
> Fix this by using the generic lseek operation.
> 
> Fixes: 71adefd254f2 ("UBUNTU: Add ubuntu-host module")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   ubuntu/ubuntu-host/ubuntu-host.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/ubuntu/ubuntu-host/ubuntu-host.c b/ubuntu/ubuntu-host/ubuntu-host.c
> index 1abd402..a4c0636 100644
> --- a/ubuntu/ubuntu-host/ubuntu-host.c
> +++ b/ubuntu/ubuntu-host/ubuntu-host.c
> @@ -38,6 +38,8 @@ static ssize_t esm_token_write(struct file *f, const char __user *buf,
>   static const struct proc_ops esm_token_fops = {
>   	.proc_read = esm_token_read,
>   	.proc_write = esm_token_write,
> +	.proc_lseek = default_llseek,
> +
>   };
>   
>   static void ubuntu_host_cleanup(void)
> 

Applied to groovy:linux and hirsute:linux.

Thanks,
Kleber
diff mbox series

Patch

diff --git a/ubuntu/ubuntu-host/ubuntu-host.c b/ubuntu/ubuntu-host/ubuntu-host.c
index 1abd402..a4c0636 100644
--- a/ubuntu/ubuntu-host/ubuntu-host.c
+++ b/ubuntu/ubuntu-host/ubuntu-host.c
@@ -38,6 +38,8 @@  static ssize_t esm_token_write(struct file *f, const char __user *buf,
 static const struct proc_ops esm_token_fops = {
 	.proc_read = esm_token_read,
 	.proc_write = esm_token_write,
+	.proc_lseek = default_llseek,
+
 };
 
 static void ubuntu_host_cleanup(void)