diff mbox series

slub/slub_kunit:fix a panic due to __kmalloc_cache_noprof incorretly use

Message ID tencent_C1486E2FA393F0B97DD7D308336E262A3407@qq.com (mailing list archive)
State New
Headers show
Series slub/slub_kunit:fix a panic due to __kmalloc_cache_noprof incorretly use | expand

Commit Message

xiaopeitux@foxmail.com Oct. 21, 2024, 6:59 a.m. UTC 
From: Pei Xiao <xiaopei01@kylinos.cn>

'modprobe slub_kunit',will have a panic.The root cause is that
__kmalloc_cache_noprof was directly ,which resulted in no alloc_tag
being allocated.This caused current->alloc_tag to be null,leading to
a null pointer dereference in alloc_tag_ref_set.

Here is the log for the panic:
[   74.779373][ T2158] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
[   74.780130][ T2158] Mem abort info:
[   74.780406][ T2158]   ESR = 0x0000000096000004
[   74.780756][ T2158]   EC = 0x25: DABT (current EL), IL = 32 bits
[   74.781225][ T2158]   SET = 0, FnV = 0
[   74.781529][ T2158]   EA = 0, S1PTW = 0
[   74.781836][ T2158]   FSC = 0x04: level 0 translation fault
[   74.782288][ T2158] Data abort info:
[   74.782577][ T2158]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[   74.783068][ T2158]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   74.783533][ T2158]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   74.784010][ T2158] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000105f34000
[   74.784586][ T2158] [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
[   74.785293][ T2158] Internal error: Oops: 0000000096000004 [#1] SMP
[   74.785805][ T2158] Modules linked in: slub_kunit kunit ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle 4
[   74.790661][ T2158] CPU: 0 UID: 0 PID: 2158 Comm: kunit_try_catch Kdump: loaded Tainted: G        W        N 6.12.0-rc3+ #2
[   74.791535][ T2158] Tainted: [W]=WARN, [N]=TEST
[   74.791889][ T2158] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[   74.792479][ T2158] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   74.793101][ T2158] pc : alloc_tagging_slab_alloc_hook+0x120/0x270
[   74.793607][ T2158] lr : alloc_tagging_slab_alloc_hook+0x120/0x270

[   74.794095][ T2158] sp : ffff800084d33cd0
[   74.794418][ T2158] x29: ffff800084d33cd0 x28: 0000000000000000 x27: 0000000000000000
[   74.795095][ T2158] x26: 0000000000000000 x25: 0000000000000012 x24: ffff80007b30e314
[   74.795822][ T2158] x23: ffff000390ff6f10 x22: 0000000000000000 x21: 0000000000000088
[   74.796555][ T2158] x20: ffff000390285840 x19: fffffd7fc3ef7830 x18: ffffffffffffffff
[   74.797283][ T2158] x17: ffff8000800e63b4 x16: ffff80007b33afc4 x15: ffff800081654c00
[   74.798011][ T2158] x14: 0000000000000000 x13: 205d383531325420 x12: 5b5d383734363537
[   74.798744][ T2158] x11: ffff800084d337e0 x10: 000000000000005d x9 : 00000000ffffffd0
[   74.799476][ T2158] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008219d188 x6 : c0000000ffff7fff
[   74.800206][ T2158] x5 : ffff0003fdbc9208 x4 : ffff800081edd188 x3 : 0000000000000001
[   74.800932][ T2158] x2 : 0beaa6dee1ac5a00 x1 : 0beaa6dee1ac5a00 x0 : ffff80037c2cb000
[   74.801656][ T2158] Call trace:
[   74.801954][ T2158]  alloc_tagging_slab_alloc_hook+0x120/0x270
[   74.802494][ T2158]  __kmalloc_cache_noprof+0x148/0x33c
[   74.802976][ T2158]  test_kmalloc_redzone_access+0x4c/0x104 [slub_kunit]
[   74.803607][ T2158]  kunit_try_run_case+0x70/0x17c [kunit]
[   74.804124][ T2158]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
[   74.804768][ T2158]  kthread+0x10c/0x118
[   74.805141][ T2158]  ret_from_fork+0x10/0x20
[   74.805540][ T2158] Code: b9400a80 11000400 b9000a80 97ffd858 (f94012d3)
[   74.806176][ T2158] SMP: stopping secondary CPUs
[   74.808130][ T2158] Starting crashdump kernel...

Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
---
 include/linux/slab.h | 1 +
 lib/slub_kunit.c     | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

Comments

Suren Baghdasaryan Oct. 21, 2024, 5:42 p.m. UTC | #1 
On Sun, Oct 20, 2024 at 11:59 PM <xiaopeitux@foxmail.com> wrote:
>
> From: Pei Xiao <xiaopei01@kylinos.cn>
>
> 'modprobe slub_kunit',will have a panic.The root cause is that
> __kmalloc_cache_noprof was directly ,which resulted in no alloc_tag
> being allocated.This caused current->alloc_tag to be null,leading to
> a null pointer dereference in alloc_tag_ref_set.

I think the root cause of this crash is the bug that is fixed by
https://lore.kernel.org/all/20241020070819.307944-1-hao.ge@linux.dev/.
Do you get this crash if you apply that fix?

>
> Here is the log for the panic:
> [   74.779373][ T2158] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
> [   74.780130][ T2158] Mem abort info:
> [   74.780406][ T2158]   ESR = 0x0000000096000004
> [   74.780756][ T2158]   EC = 0x25: DABT (current EL), IL = 32 bits
> [   74.781225][ T2158]   SET = 0, FnV = 0
> [   74.781529][ T2158]   EA = 0, S1PTW = 0
> [   74.781836][ T2158]   FSC = 0x04: level 0 translation fault
> [   74.782288][ T2158] Data abort info:
> [   74.782577][ T2158]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> [   74.783068][ T2158]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> [   74.783533][ T2158]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [   74.784010][ T2158] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000105f34000
> [   74.784586][ T2158] [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
> [   74.785293][ T2158] Internal error: Oops: 0000000096000004 [#1] SMP
> [   74.785805][ T2158] Modules linked in: slub_kunit kunit ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle 4
> [   74.790661][ T2158] CPU: 0 UID: 0 PID: 2158 Comm: kunit_try_catch Kdump: loaded Tainted: G        W        N 6.12.0-rc3+ #2
> [   74.791535][ T2158] Tainted: [W]=WARN, [N]=TEST
> [   74.791889][ T2158] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
> [   74.792479][ T2158] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [   74.793101][ T2158] pc : alloc_tagging_slab_alloc_hook+0x120/0x270
> [   74.793607][ T2158] lr : alloc_tagging_slab_alloc_hook+0x120/0x270
>
> [   74.794095][ T2158] sp : ffff800084d33cd0
> [   74.794418][ T2158] x29: ffff800084d33cd0 x28: 0000000000000000 x27: 0000000000000000
> [   74.795095][ T2158] x26: 0000000000000000 x25: 0000000000000012 x24: ffff80007b30e314
> [   74.795822][ T2158] x23: ffff000390ff6f10 x22: 0000000000000000 x21: 0000000000000088
> [   74.796555][ T2158] x20: ffff000390285840 x19: fffffd7fc3ef7830 x18: ffffffffffffffff
> [   74.797283][ T2158] x17: ffff8000800e63b4 x16: ffff80007b33afc4 x15: ffff800081654c00
> [   74.798011][ T2158] x14: 0000000000000000 x13: 205d383531325420 x12: 5b5d383734363537
> [   74.798744][ T2158] x11: ffff800084d337e0 x10: 000000000000005d x9 : 00000000ffffffd0
> [   74.799476][ T2158] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008219d188 x6 : c0000000ffff7fff
> [   74.800206][ T2158] x5 : ffff0003fdbc9208 x4 : ffff800081edd188 x3 : 0000000000000001
> [   74.800932][ T2158] x2 : 0beaa6dee1ac5a00 x1 : 0beaa6dee1ac5a00 x0 : ffff80037c2cb000
> [   74.801656][ T2158] Call trace:
> [   74.801954][ T2158]  alloc_tagging_slab_alloc_hook+0x120/0x270
> [   74.802494][ T2158]  __kmalloc_cache_noprof+0x148/0x33c
> [   74.802976][ T2158]  test_kmalloc_redzone_access+0x4c/0x104 [slub_kunit]
> [   74.803607][ T2158]  kunit_try_run_case+0x70/0x17c [kunit]
> [   74.804124][ T2158]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
> [   74.804768][ T2158]  kthread+0x10c/0x118
> [   74.805141][ T2158]  ret_from_fork+0x10/0x20
> [   74.805540][ T2158] Code: b9400a80 11000400 b9000a80 97ffd858 (f94012d3)
> [   74.806176][ T2158] SMP: stopping secondary CPUs
> [   74.808130][ T2158] Starting crashdump kernel...
>

CC'ing Vlastimil.
This patch essentially reverts Vlastimil's "mm, slab: don't wrap
internal functions with alloc_hooks()" change. Please check why that
change was needed before proceeding.
If this change is indeed needed, please add:

Fixes: a0a44d9175b349 ("mm, slab: don't wrap internal functions with
alloc_hooks()")

> Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
> ---
>  include/linux/slab.h | 1 +
>  lib/slub_kunit.c     | 2 +-
>  2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 10a971c2bde3..0149d36cd311 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -827,6 +827,7 @@ void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t flags, size_t size)
>  void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags,
>                                   int node, size_t size)
>                                 __assume_kmalloc_alignment __alloc_size(4);
> +#define kmalloc_cache(...)     alloc_hooks(__kmalloc_cache_noprof(__VA_ARGS__))
>
>  void *__kmalloc_large_noprof(size_t size, gfp_t flags)
>                                 __assume_page_alignment __alloc_size(1);
> diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c
> index 80e39f003344..4bf38f52dbbd 100644
> --- a/lib/slub_kunit.c
> +++ b/lib/slub_kunit.c
> @@ -141,7 +141,7 @@ static void test_kmalloc_redzone_access(struct kunit *test)
>  {
>         struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
>                                 SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
> -       u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18);
> +       u8 *p = kmalloc_cache(s, GFP_KERNEL, 18);
>
>         kasan_disable_current();
>
> --
> 2.34.1
>
Hao Ge Oct. 22, 2024, 2:19 a.m. UTC | #2 
On 10/22/24 01:42, Suren Baghdasaryan wrote:
> On Sun, Oct 20, 2024 at 11:59 PM <xiaopeitux@foxmail.com> wrote:
>> From: Pei Xiao <xiaopei01@kylinos.cn>
>>
>> 'modprobe slub_kunit',will have a panic.The root cause is that
>> __kmalloc_cache_noprof was directly ,which resulted in no alloc_tag
>> being allocated.This caused current->alloc_tag to be null,leading to
>> a null pointer dereference in alloc_tag_ref_set.
> I think the root cause of this crash is the bug that is fixed by
> https://lore.kernel.org/all/20241020070819.307944-1-hao.ge@linux.dev/.
> Do you get this crash if you apply that fix?
Yes, this patch has resolved the panic issue.
>> Here is the log for the panic:
>> [   74.779373][ T2158] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
>> [   74.780130][ T2158] Mem abort info:
>> [   74.780406][ T2158]   ESR = 0x0000000096000004
>> [   74.780756][ T2158]   EC = 0x25: DABT (current EL), IL = 32 bits
>> [   74.781225][ T2158]   SET = 0, FnV = 0
>> [   74.781529][ T2158]   EA = 0, S1PTW = 0
>> [   74.781836][ T2158]   FSC = 0x04: level 0 translation fault
>> [   74.782288][ T2158] Data abort info:
>> [   74.782577][ T2158]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
>> [   74.783068][ T2158]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
>> [   74.783533][ T2158]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>> [   74.784010][ T2158] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000105f34000
>> [   74.784586][ T2158] [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
>> [   74.785293][ T2158] Internal error: Oops: 0000000096000004 [#1] SMP
>> [   74.785805][ T2158] Modules linked in: slub_kunit kunit ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle 4
>> [   74.790661][ T2158] CPU: 0 UID: 0 PID: 2158 Comm: kunit_try_catch Kdump: loaded Tainted: G        W        N 6.12.0-rc3+ #2
>> [   74.791535][ T2158] Tainted: [W]=WARN, [N]=TEST
>> [   74.791889][ T2158] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
>> [   74.792479][ T2158] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>> [   74.793101][ T2158] pc : alloc_tagging_slab_alloc_hook+0x120/0x270
>> [   74.793607][ T2158] lr : alloc_tagging_slab_alloc_hook+0x120/0x270
>>
>> [   74.794095][ T2158] sp : ffff800084d33cd0
>> [   74.794418][ T2158] x29: ffff800084d33cd0 x28: 0000000000000000 x27: 0000000000000000
>> [   74.795095][ T2158] x26: 0000000000000000 x25: 0000000000000012 x24: ffff80007b30e314
>> [   74.795822][ T2158] x23: ffff000390ff6f10 x22: 0000000000000000 x21: 0000000000000088
>> [   74.796555][ T2158] x20: ffff000390285840 x19: fffffd7fc3ef7830 x18: ffffffffffffffff
>> [   74.797283][ T2158] x17: ffff8000800e63b4 x16: ffff80007b33afc4 x15: ffff800081654c00
>> [   74.798011][ T2158] x14: 0000000000000000 x13: 205d383531325420 x12: 5b5d383734363537
>> [   74.798744][ T2158] x11: ffff800084d337e0 x10: 000000000000005d x9 : 00000000ffffffd0
>> [   74.799476][ T2158] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008219d188 x6 : c0000000ffff7fff
>> [   74.800206][ T2158] x5 : ffff0003fdbc9208 x4 : ffff800081edd188 x3 : 0000000000000001
>> [   74.800932][ T2158] x2 : 0beaa6dee1ac5a00 x1 : 0beaa6dee1ac5a00 x0 : ffff80037c2cb000
>> [   74.801656][ T2158] Call trace:
>> [   74.801954][ T2158]  alloc_tagging_slab_alloc_hook+0x120/0x270
>> [   74.802494][ T2158]  __kmalloc_cache_noprof+0x148/0x33c
>> [   74.802976][ T2158]  test_kmalloc_redzone_access+0x4c/0x104 [slub_kunit]
>> [   74.803607][ T2158]  kunit_try_run_case+0x70/0x17c [kunit]
>> [   74.804124][ T2158]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
>> [   74.804768][ T2158]  kthread+0x10c/0x118
>> [   74.805141][ T2158]  ret_from_fork+0x10/0x20
>> [   74.805540][ T2158] Code: b9400a80 11000400 b9000a80 97ffd858 (f94012d3)
>> [   74.806176][ T2158] SMP: stopping secondary CPUs
>> [   74.808130][ T2158] Starting crashdump kernel...
>>
> CC'ing Vlastimil.
> This patch essentially reverts Vlastimil's "mm, slab: don't wrap
> internal functions with alloc_hooks()" change. Please check why that
> change was needed before proceeding.
> If this change is indeed needed, please add:

Hi Suren and Vlastimil

In fact, besides the panic, there is also a warning here due to directly 
invoking__kmalloc_cache_noprof

Regarding this, do you have any suggestions?

[58162.947016] WARNING: CPU: 2 PID: 6210 at 
./include/linux/alloc_tag.h:125 alloc_tagging_slab_alloc_hook+0x268/0x27c
[58162.957721] Call trace:
[58162.957919]  alloc_tagging_slab_alloc_hook+0x268/0x27c
[58162.958286]  __kmalloc_cache_noprof+0x14c/0x344
[58162.958615]  test_kmalloc_redzone_access+0x50/0x10c [slub_kunit]
[58162.959045]  kunit_try_run_case+0x74/0x184 [kunit]
[58162.959401]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
[58162.959841]  kthread+0x10c/0x118
[58162.960093]  ret_from_fork+0x10/0x20
[58162.960363] ---[ end trace 0000000000000000 ]---


Thanks

Best regards

Hao

>
> Fixes: a0a44d9175b349 ("mm, slab: don't wrap internal functions with
> alloc_hooks()")
>
>> Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
>> ---
>>   include/linux/slab.h | 1 +
>>   lib/slub_kunit.c     | 2 +-
>>   2 files changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/linux/slab.h b/include/linux/slab.h
>> index 10a971c2bde3..0149d36cd311 100644
>> --- a/include/linux/slab.h
>> +++ b/include/linux/slab.h
>> @@ -827,6 +827,7 @@ void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t flags, size_t size)
>>   void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags,
>>                                    int node, size_t size)
>>                                  __assume_kmalloc_alignment __alloc_size(4);
>> +#define kmalloc_cache(...)     alloc_hooks(__kmalloc_cache_noprof(__VA_ARGS__))
>>
>>   void *__kmalloc_large_noprof(size_t size, gfp_t flags)
>>                                  __assume_page_alignment __alloc_size(1);
>> diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c
>> index 80e39f003344..4bf38f52dbbd 100644
>> --- a/lib/slub_kunit.c
>> +++ b/lib/slub_kunit.c
>> @@ -141,7 +141,7 @@ static void test_kmalloc_redzone_access(struct kunit *test)
>>   {
>>          struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
>>                                  SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
>> -       u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18);
>> +       u8 *p = kmalloc_cache(s, GFP_KERNEL, 18);
>>
>>          kasan_disable_current();
>>
>> --
>> 2.34.1
>>
Vlastimil Babka Oct. 22, 2024, 3:27 p.m. UTC | #3 
On 10/22/24 04:19, Hao Ge wrote:
> 
> On 10/22/24 01:42, Suren Baghdasaryan wrote:
>> On Sun, Oct 20, 2024 at 11:59 PM <xiaopeitux@foxmail.com> wrote:
>>> From: Pei Xiao <xiaopei01@kylinos.cn>
>>>
>>> 'modprobe slub_kunit',will have a panic.The root cause is that
>>> __kmalloc_cache_noprof was directly ,which resulted in no alloc_tag
>>> being allocated.This caused current->alloc_tag to be null,leading to
>>> a null pointer dereference in alloc_tag_ref_set.
>> I think the root cause of this crash is the bug that is fixed by
>> https://lore.kernel.org/all/20241020070819.307944-1-hao.ge@linux.dev/.
>> Do you get this crash if you apply that fix?
> Yes, this patch has resolved the panic issue.
>>> Here is the log for the panic:
>>> [   74.779373][ T2158] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
>>> [   74.780130][ T2158] Mem abort info:
>>> [   74.780406][ T2158]   ESR = 0x0000000096000004
>>> [   74.780756][ T2158]   EC = 0x25: DABT (current EL), IL = 32 bits
>>> [   74.781225][ T2158]   SET = 0, FnV = 0
>>> [   74.781529][ T2158]   EA = 0, S1PTW = 0
>>> [   74.781836][ T2158]   FSC = 0x04: level 0 translation fault
>>> [   74.782288][ T2158] Data abort info:
>>> [   74.782577][ T2158]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
>>> [   74.783068][ T2158]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
>>> [   74.783533][ T2158]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>>> [   74.784010][ T2158] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000105f34000
>>> [   74.784586][ T2158] [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
>>> [   74.785293][ T2158] Internal error: Oops: 0000000096000004 [#1] SMP
>>> [   74.785805][ T2158] Modules linked in: slub_kunit kunit ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle 4
>>> [   74.790661][ T2158] CPU: 0 UID: 0 PID: 2158 Comm: kunit_try_catch Kdump: loaded Tainted: G        W        N 6.12.0-rc3+ #2
>>> [   74.791535][ T2158] Tainted: [W]=WARN, [N]=TEST
>>> [   74.791889][ T2158] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
>>> [   74.792479][ T2158] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>> [   74.793101][ T2158] pc : alloc_tagging_slab_alloc_hook+0x120/0x270
>>> [   74.793607][ T2158] lr : alloc_tagging_slab_alloc_hook+0x120/0x270
>>>
>>> [   74.794095][ T2158] sp : ffff800084d33cd0
>>> [   74.794418][ T2158] x29: ffff800084d33cd0 x28: 0000000000000000 x27: 0000000000000000
>>> [   74.795095][ T2158] x26: 0000000000000000 x25: 0000000000000012 x24: ffff80007b30e314
>>> [   74.795822][ T2158] x23: ffff000390ff6f10 x22: 0000000000000000 x21: 0000000000000088
>>> [   74.796555][ T2158] x20: ffff000390285840 x19: fffffd7fc3ef7830 x18: ffffffffffffffff
>>> [   74.797283][ T2158] x17: ffff8000800e63b4 x16: ffff80007b33afc4 x15: ffff800081654c00
>>> [   74.798011][ T2158] x14: 0000000000000000 x13: 205d383531325420 x12: 5b5d383734363537
>>> [   74.798744][ T2158] x11: ffff800084d337e0 x10: 000000000000005d x9 : 00000000ffffffd0
>>> [   74.799476][ T2158] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008219d188 x6 : c0000000ffff7fff
>>> [   74.800206][ T2158] x5 : ffff0003fdbc9208 x4 : ffff800081edd188 x3 : 0000000000000001
>>> [   74.800932][ T2158] x2 : 0beaa6dee1ac5a00 x1 : 0beaa6dee1ac5a00 x0 : ffff80037c2cb000
>>> [   74.801656][ T2158] Call trace:
>>> [   74.801954][ T2158]  alloc_tagging_slab_alloc_hook+0x120/0x270
>>> [   74.802494][ T2158]  __kmalloc_cache_noprof+0x148/0x33c
>>> [   74.802976][ T2158]  test_kmalloc_redzone_access+0x4c/0x104 [slub_kunit]
>>> [   74.803607][ T2158]  kunit_try_run_case+0x70/0x17c [kunit]
>>> [   74.804124][ T2158]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
>>> [   74.804768][ T2158]  kthread+0x10c/0x118
>>> [   74.805141][ T2158]  ret_from_fork+0x10/0x20
>>> [   74.805540][ T2158] Code: b9400a80 11000400 b9000a80 97ffd858 (f94012d3)
>>> [   74.806176][ T2158] SMP: stopping secondary CPUs
>>> [   74.808130][ T2158] Starting crashdump kernel...
>>>
>> CC'ing Vlastimil.
>> This patch essentially reverts Vlastimil's "mm, slab: don't wrap
>> internal functions with alloc_hooks()" change. Please check why that
>> change was needed before proceeding.
>> If this change is indeed needed, please add:
> 
> Hi Suren and Vlastimil
> 
> In fact, besides the panic, there is also a warning here due to directly 
> invoking__kmalloc_cache_noprof
> 
> Regarding this, do you have any suggestions?
> 
> [58162.947016] WARNING: CPU: 2 PID: 6210 at 
> ./include/linux/alloc_tag.h:125 alloc_tagging_slab_alloc_hook+0x268/0x27c
> [58162.957721] Call trace:
> [58162.957919]  alloc_tagging_slab_alloc_hook+0x268/0x27c
> [58162.958286]  __kmalloc_cache_noprof+0x14c/0x344
> [58162.958615]  test_kmalloc_redzone_access+0x50/0x10c [slub_kunit]
> [58162.959045]  kunit_try_run_case+0x74/0x184 [kunit]
> [58162.959401]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
> [58162.959841]  kthread+0x10c/0x118
> [58162.960093]  ret_from_fork+0x10/0x20
> [58162.960363] ---[ end trace 0000000000000000 ]---

I see.
The kunit test is the only user of __kmalloc_cache_noprof outside of kmalloc()
itself so it's not worth defining again a wrapper for everyone, how about just
wrapping the two callsites?

--- a/lib/slub_kunit.c
+++ b/lib/slub_kunit.c
@@ -141,7 +141,7 @@ static void test_kmalloc_redzone_access(struct kunit *test)
 {
        struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
                                SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
-       u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18);
+       u8 *p = alloc_hooks(__kmalloc_cache_noprof(s, GFP_KERNEL, 18));
 
        kasan_disable_current();
 
@@ -199,7 +199,7 @@ static void test_krealloc_redzone_zeroing(struct kunit *test)
        struct kmem_cache *s = test_kmem_cache_create("TestSlub_krealloc", 64,
                                SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
 
-       p = __kmalloc_cache_noprof(s, GFP_KERNEL, 48);
+       p = alloc_hooks(__kmalloc_cache_noprof(s, GFP_KERNEL, 48));
        memset(p, 0xff, 48);
 
        kasan_disable_current();
Hao Ge Oct. 23, 2024, 1:47 a.m. UTC | #4 
On 10/22/24 23:27, Vlastimil Babka wrote:
> On 10/22/24 04:19, Hao Ge wrote:
>> On 10/22/24 01:42, Suren Baghdasaryan wrote:
>>> On Sun, Oct 20, 2024 at 11:59 PM <xiaopeitux@foxmail.com> wrote:
>>>> From: Pei Xiao <xiaopei01@kylinos.cn>
>>>>
>>>> 'modprobe slub_kunit',will have a panic.The root cause is that
>>>> __kmalloc_cache_noprof was directly ,which resulted in no alloc_tag
>>>> being allocated.This caused current->alloc_tag to be null,leading to
>>>> a null pointer dereference in alloc_tag_ref_set.
>>> I think the root cause of this crash is the bug that is fixed by
>>> https://lore.kernel.org/all/20241020070819.307944-1-hao.ge@linux.dev/.
>>> Do you get this crash if you apply that fix?
>> Yes, this patch has resolved the panic issue.
>>>> Here is the log for the panic:
>>>> [   74.779373][ T2158] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
>>>> [   74.780130][ T2158] Mem abort info:
>>>> [   74.780406][ T2158]   ESR = 0x0000000096000004
>>>> [   74.780756][ T2158]   EC = 0x25: DABT (current EL), IL = 32 bits
>>>> [   74.781225][ T2158]   SET = 0, FnV = 0
>>>> [   74.781529][ T2158]   EA = 0, S1PTW = 0
>>>> [   74.781836][ T2158]   FSC = 0x04: level 0 translation fault
>>>> [   74.782288][ T2158] Data abort info:
>>>> [   74.782577][ T2158]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
>>>> [   74.783068][ T2158]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
>>>> [   74.783533][ T2158]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>>>> [   74.784010][ T2158] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000105f34000
>>>> [   74.784586][ T2158] [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
>>>> [   74.785293][ T2158] Internal error: Oops: 0000000096000004 [#1] SMP
>>>> [   74.785805][ T2158] Modules linked in: slub_kunit kunit ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle 4
>>>> [   74.790661][ T2158] CPU: 0 UID: 0 PID: 2158 Comm: kunit_try_catch Kdump: loaded Tainted: G        W        N 6.12.0-rc3+ #2
>>>> [   74.791535][ T2158] Tainted: [W]=WARN, [N]=TEST
>>>> [   74.791889][ T2158] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
>>>> [   74.792479][ T2158] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>>> [   74.793101][ T2158] pc : alloc_tagging_slab_alloc_hook+0x120/0x270
>>>> [   74.793607][ T2158] lr : alloc_tagging_slab_alloc_hook+0x120/0x270
>>>>
>>>> [   74.794095][ T2158] sp : ffff800084d33cd0
>>>> [   74.794418][ T2158] x29: ffff800084d33cd0 x28: 0000000000000000 x27: 0000000000000000
>>>> [   74.795095][ T2158] x26: 0000000000000000 x25: 0000000000000012 x24: ffff80007b30e314
>>>> [   74.795822][ T2158] x23: ffff000390ff6f10 x22: 0000000000000000 x21: 0000000000000088
>>>> [   74.796555][ T2158] x20: ffff000390285840 x19: fffffd7fc3ef7830 x18: ffffffffffffffff
>>>> [   74.797283][ T2158] x17: ffff8000800e63b4 x16: ffff80007b33afc4 x15: ffff800081654c00
>>>> [   74.798011][ T2158] x14: 0000000000000000 x13: 205d383531325420 x12: 5b5d383734363537
>>>> [   74.798744][ T2158] x11: ffff800084d337e0 x10: 000000000000005d x9 : 00000000ffffffd0
>>>> [   74.799476][ T2158] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008219d188 x6 : c0000000ffff7fff
>>>> [   74.800206][ T2158] x5 : ffff0003fdbc9208 x4 : ffff800081edd188 x3 : 0000000000000001
>>>> [   74.800932][ T2158] x2 : 0beaa6dee1ac5a00 x1 : 0beaa6dee1ac5a00 x0 : ffff80037c2cb000
>>>> [   74.801656][ T2158] Call trace:
>>>> [   74.801954][ T2158]  alloc_tagging_slab_alloc_hook+0x120/0x270
>>>> [   74.802494][ T2158]  __kmalloc_cache_noprof+0x148/0x33c
>>>> [   74.802976][ T2158]  test_kmalloc_redzone_access+0x4c/0x104 [slub_kunit]
>>>> [   74.803607][ T2158]  kunit_try_run_case+0x70/0x17c [kunit]
>>>> [   74.804124][ T2158]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
>>>> [   74.804768][ T2158]  kthread+0x10c/0x118
>>>> [   74.805141][ T2158]  ret_from_fork+0x10/0x20
>>>> [   74.805540][ T2158] Code: b9400a80 11000400 b9000a80 97ffd858 (f94012d3)
>>>> [   74.806176][ T2158] SMP: stopping secondary CPUs
>>>> [   74.808130][ T2158] Starting crashdump kernel...
>>>>
>>> CC'ing Vlastimil.
>>> This patch essentially reverts Vlastimil's "mm, slab: don't wrap
>>> internal functions with alloc_hooks()" change. Please check why that
>>> change was needed before proceeding.
>>> If this change is indeed needed, please add:
>> Hi Suren and Vlastimil
>>
>> In fact, besides the panic, there is also a warning here due to directly
>> invoking__kmalloc_cache_noprof
>>
>> Regarding this, do you have any suggestions?
>>
>> [58162.947016] WARNING: CPU: 2 PID: 6210 at
>> ./include/linux/alloc_tag.h:125 alloc_tagging_slab_alloc_hook+0x268/0x27c
>> [58162.957721] Call trace:
>> [58162.957919]  alloc_tagging_slab_alloc_hook+0x268/0x27c
>> [58162.958286]  __kmalloc_cache_noprof+0x14c/0x344
>> [58162.958615]  test_kmalloc_redzone_access+0x50/0x10c [slub_kunit]
>> [58162.959045]  kunit_try_run_case+0x74/0x184 [kunit]
>> [58162.959401]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
>> [58162.959841]  kthread+0x10c/0x118
>> [58162.960093]  ret_from_fork+0x10/0x20
>> [58162.960363] ---[ end trace 0000000000000000 ]---
> I see.
> The kunit test is the only user of __kmalloc_cache_noprof outside of kmalloc()
> itself so it's not worth defining again a wrapper for everyone, how about just
> wrapping the two callsites?
>
> --- a/lib/slub_kunit.c
> +++ b/lib/slub_kunit.c
> @@ -141,7 +141,7 @@ static void test_kmalloc_redzone_access(struct kunit *test)
>   {
>          struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
>                                  SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
> -       u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18);
> +       u8 *p = alloc_hooks(__kmalloc_cache_noprof(s, GFP_KERNEL, 18));
>   
>          kasan_disable_current();
>   
> @@ -199,7 +199,7 @@ static void test_krealloc_redzone_zeroing(struct kunit *test)
>          struct kmem_cache *s = test_kmem_cache_create("TestSlub_krealloc", 64,
>                                  SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
>   
> -       p = __kmalloc_cache_noprof(s, GFP_KERNEL, 48);
> +       p = alloc_hooks(__kmalloc_cache_noprof(s, GFP_KERNEL, 48));
>          memset(p, 0xff, 48);
>   
>          kasan_disable_current();
>
Hi  Vlastimil

I agree with your point of view, thank you for you and Suren's help and 
suggestion.

Best regards

Hao
Suren Baghdasaryan Oct. 23, 2024, 1:58 a.m. UTC | #5 
On Tue, Oct 22, 2024 at 6:47 PM Hao Ge <hao.ge@linux.dev> wrote:
>
>
> On 10/22/24 23:27, Vlastimil Babka wrote:
> > On 10/22/24 04:19, Hao Ge wrote:
> >> On 10/22/24 01:42, Suren Baghdasaryan wrote:
> >>> On Sun, Oct 20, 2024 at 11:59 PM <xiaopeitux@foxmail.com> wrote:
> >>>> From: Pei Xiao <xiaopei01@kylinos.cn>
> >>>>
> >>>> 'modprobe slub_kunit',will have a panic.The root cause is that
> >>>> __kmalloc_cache_noprof was directly ,which resulted in no alloc_tag
> >>>> being allocated.This caused current->alloc_tag to be null,leading to
> >>>> a null pointer dereference in alloc_tag_ref_set.
> >>> I think the root cause of this crash is the bug that is fixed by
> >>> https://lore.kernel.org/all/20241020070819.307944-1-hao.ge@linux.dev/.
> >>> Do you get this crash if you apply that fix?
> >> Yes, this patch has resolved the panic issue.
> >>>> Here is the log for the panic:
> >>>> [   74.779373][ T2158] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
> >>>> [   74.780130][ T2158] Mem abort info:
> >>>> [   74.780406][ T2158]   ESR = 0x0000000096000004
> >>>> [   74.780756][ T2158]   EC = 0x25: DABT (current EL), IL = 32 bits
> >>>> [   74.781225][ T2158]   SET = 0, FnV = 0
> >>>> [   74.781529][ T2158]   EA = 0, S1PTW = 0
> >>>> [   74.781836][ T2158]   FSC = 0x04: level 0 translation fault
> >>>> [   74.782288][ T2158] Data abort info:
> >>>> [   74.782577][ T2158]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> >>>> [   74.783068][ T2158]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> >>>> [   74.783533][ T2158]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> >>>> [   74.784010][ T2158] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000105f34000
> >>>> [   74.784586][ T2158] [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
> >>>> [   74.785293][ T2158] Internal error: Oops: 0000000096000004 [#1] SMP
> >>>> [   74.785805][ T2158] Modules linked in: slub_kunit kunit ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle 4
> >>>> [   74.790661][ T2158] CPU: 0 UID: 0 PID: 2158 Comm: kunit_try_catch Kdump: loaded Tainted: G        W        N 6.12.0-rc3+ #2
> >>>> [   74.791535][ T2158] Tainted: [W]=WARN, [N]=TEST
> >>>> [   74.791889][ T2158] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
> >>>> [   74.792479][ T2158] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> >>>> [   74.793101][ T2158] pc : alloc_tagging_slab_alloc_hook+0x120/0x270
> >>>> [   74.793607][ T2158] lr : alloc_tagging_slab_alloc_hook+0x120/0x270
> >>>>
> >>>> [   74.794095][ T2158] sp : ffff800084d33cd0
> >>>> [   74.794418][ T2158] x29: ffff800084d33cd0 x28: 0000000000000000 x27: 0000000000000000
> >>>> [   74.795095][ T2158] x26: 0000000000000000 x25: 0000000000000012 x24: ffff80007b30e314
> >>>> [   74.795822][ T2158] x23: ffff000390ff6f10 x22: 0000000000000000 x21: 0000000000000088
> >>>> [   74.796555][ T2158] x20: ffff000390285840 x19: fffffd7fc3ef7830 x18: ffffffffffffffff
> >>>> [   74.797283][ T2158] x17: ffff8000800e63b4 x16: ffff80007b33afc4 x15: ffff800081654c00
> >>>> [   74.798011][ T2158] x14: 0000000000000000 x13: 205d383531325420 x12: 5b5d383734363537
> >>>> [   74.798744][ T2158] x11: ffff800084d337e0 x10: 000000000000005d x9 : 00000000ffffffd0
> >>>> [   74.799476][ T2158] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008219d188 x6 : c0000000ffff7fff
> >>>> [   74.800206][ T2158] x5 : ffff0003fdbc9208 x4 : ffff800081edd188 x3 : 0000000000000001
> >>>> [   74.800932][ T2158] x2 : 0beaa6dee1ac5a00 x1 : 0beaa6dee1ac5a00 x0 : ffff80037c2cb000
> >>>> [   74.801656][ T2158] Call trace:
> >>>> [   74.801954][ T2158]  alloc_tagging_slab_alloc_hook+0x120/0x270
> >>>> [   74.802494][ T2158]  __kmalloc_cache_noprof+0x148/0x33c
> >>>> [   74.802976][ T2158]  test_kmalloc_redzone_access+0x4c/0x104 [slub_kunit]
> >>>> [   74.803607][ T2158]  kunit_try_run_case+0x70/0x17c [kunit]
> >>>> [   74.804124][ T2158]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
> >>>> [   74.804768][ T2158]  kthread+0x10c/0x118
> >>>> [   74.805141][ T2158]  ret_from_fork+0x10/0x20
> >>>> [   74.805540][ T2158] Code: b9400a80 11000400 b9000a80 97ffd858 (f94012d3)
> >>>> [   74.806176][ T2158] SMP: stopping secondary CPUs
> >>>> [   74.808130][ T2158] Starting crashdump kernel...
> >>>>
> >>> CC'ing Vlastimil.
> >>> This patch essentially reverts Vlastimil's "mm, slab: don't wrap
> >>> internal functions with alloc_hooks()" change. Please check why that
> >>> change was needed before proceeding.
> >>> If this change is indeed needed, please add:
> >> Hi Suren and Vlastimil
> >>
> >> In fact, besides the panic, there is also a warning here due to directly
> >> invoking__kmalloc_cache_noprof
> >>
> >> Regarding this, do you have any suggestions?
> >>
> >> [58162.947016] WARNING: CPU: 2 PID: 6210 at
> >> ./include/linux/alloc_tag.h:125 alloc_tagging_slab_alloc_hook+0x268/0x27c
> >> [58162.957721] Call trace:
> >> [58162.957919]  alloc_tagging_slab_alloc_hook+0x268/0x27c
> >> [58162.958286]  __kmalloc_cache_noprof+0x14c/0x344
> >> [58162.958615]  test_kmalloc_redzone_access+0x50/0x10c [slub_kunit]
> >> [58162.959045]  kunit_try_run_case+0x74/0x184 [kunit]
> >> [58162.959401]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
> >> [58162.959841]  kthread+0x10c/0x118
> >> [58162.960093]  ret_from_fork+0x10/0x20
> >> [58162.960363] ---[ end trace 0000000000000000 ]---
> > I see.
> > The kunit test is the only user of __kmalloc_cache_noprof outside of kmalloc()
> > itself so it's not worth defining again a wrapper for everyone, how about just
> > wrapping the two callsites?
> >
> > --- a/lib/slub_kunit.c
> > +++ b/lib/slub_kunit.c
> > @@ -141,7 +141,7 @@ static void test_kmalloc_redzone_access(struct kunit *test)
> >   {
> >          struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
> >                                  SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
> > -       u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18);
> > +       u8 *p = alloc_hooks(__kmalloc_cache_noprof(s, GFP_KERNEL, 18));
> >
> >          kasan_disable_current();
> >
> > @@ -199,7 +199,7 @@ static void test_krealloc_redzone_zeroing(struct kunit *test)
> >          struct kmem_cache *s = test_kmem_cache_create("TestSlub_krealloc", 64,
> >                                  SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
> >
> > -       p = __kmalloc_cache_noprof(s, GFP_KERNEL, 48);
> > +       p = alloc_hooks(__kmalloc_cache_noprof(s, GFP_KERNEL, 48));
> >          memset(p, 0xff, 48);
> >
> >          kasan_disable_current();
> >
> Hi  Vlastimil
>
> I agree with your point of view, thank you for you and Suren's help and
> suggestion.

That seems reasonable to me. Thanks!

>
> Best regards
>
> Hao
>
diff mbox series

Patch

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 10a971c2bde3..0149d36cd311 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -827,6 +827,7 @@  void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t flags, size_t size)
 void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags,
 				  int node, size_t size)
 				__assume_kmalloc_alignment __alloc_size(4);
+#define kmalloc_cache(...)	alloc_hooks(__kmalloc_cache_noprof(__VA_ARGS__))
 
 void *__kmalloc_large_noprof(size_t size, gfp_t flags)
 				__assume_page_alignment __alloc_size(1);
diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c
index 80e39f003344..4bf38f52dbbd 100644
--- a/lib/slub_kunit.c
+++ b/lib/slub_kunit.c
@@ -141,7 +141,7 @@  static void test_kmalloc_redzone_access(struct kunit *test)
 {
 	struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
 				SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
-	u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18);
+	u8 *p = kmalloc_cache(s, GFP_KERNEL, 18);
 
 	kasan_disable_current();