lib/kunit/string-stream.c | 1 + 1 file changed, 1 insertion(+)
In kunit_debugfs_create_suite(), if alloc_string_stream() fails in the
kunit_suite_for_each_test_case() loop, the "suite->log = stream"
has assigned before, and the error path only free the suite->log's stream
memory but not set it to NULL in string_stream_destroy(), so the later
string_stream_clear() of suite->log in kunit_init_suite() will cause
below UAF bug.
Set stream pointer to NULL after free in string_stream_destroy()
to fix it.
Unable to handle kernel paging request at virtual address 006440150000030d
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[006440150000030d] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in: iio_test_gts industrialio_gts_helper cfg80211 rfkill ipv6 [last unloaded: iio_test_gts]
CPU: 5 UID: 0 PID: 6253 Comm: modprobe Tainted: G B W N 6.12.0-rc4+ #458
Tainted: [B]=BAD_PAGE, [W]=WARN, [N]=TEST
Hardware name: linux,dummy-virt (DT)
pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : string_stream_clear+0x54/0x1ac
lr : string_stream_clear+0x1a8/0x1ac
sp : ffffffc080b47410
x29: ffffffc080b47410 x28: 006440550000030d x27: ffffff80c96b5e98
x26: ffffff80c96b5e80 x25: ffffffe461b3f6c0 x24: 0000000000000003
x23: ffffff80c96b5e88 x22: 1ffffff019cdf4fc x21: dfffffc000000000
x20: ffffff80ce6fa7e0 x19: 032202a80000186d x18: 0000000000001840
x17: 0000000000000000 x16: 0000000000000000 x15: ffffffe45c355cb4
x14: ffffffe45c35589c x13: ffffffe45c03da78 x12: ffffffb810168e75
x11: 1ffffff810168e74 x10: ffffffb810168e74 x9 : dfffffc000000000
x8 : 0000000000000004 x7 : 0000000000000003 x6 : 0000000000000001
x5 : ffffffc080b473a0 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000001 x1 : ffffffe462fbf620 x0 : dfffffc000000000
Call trace:
string_stream_clear+0x54/0x1ac
__kunit_test_suites_init+0x108/0x1d8
kunit_exec_run_tests+0xb8/0x100
kunit_module_notify+0x400/0x55c
notifier_call_chain+0xfc/0x3b4
blocking_notifier_call_chain+0x68/0x9c
do_init_module+0x24c/0x5c8
load_module+0x4acc/0x4e90
init_module_from_file+0xd4/0x128
idempotent_init_module+0x2d4/0x57c
__arm64_sys_finit_module+0xac/0x100
invoke_syscall+0x6c/0x258
el0_svc_common.constprop.0+0x160/0x22c
do_el0_svc+0x44/0x5c
el0_svc+0x48/0xb8
el0t_64_sync_handler+0x13c/0x158
el0t_64_sync+0x190/0x194
Code: f9400753 d2dff800 f2fbffe0 d343fe7c (38e06b80)
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Oops: Fatal exception
Cc: stable@vger.kernel.org
Fixes: a3fdf784780c ("kunit: string-stream: Decouple string_stream from kunit")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
lib/kunit/string-stream.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
index 54f4fdcbfac8..00ad518b730b 100644
--- a/lib/kunit/string-stream.c
+++ b/lib/kunit/string-stream.c
@@ -178,6 +178,7 @@ void string_stream_destroy(struct string_stream *stream)
string_stream_clear(stream);
kfree(stream);
+ stream = NULL;
}
static void resource_free_string_stream(void *p)
--
2.34.1Hi Jinjie,
On Thu, Oct 24, 2024 at 05:43:03PM +0800, Jinjie Ruan wrote:
> In kunit_debugfs_create_suite(), if alloc_string_stream() fails in the
> kunit_suite_for_each_test_case() loop, the "suite->log = stream"
> has assigned before, and the error path only free the suite->log's stream
> memory but not set it to NULL in string_stream_destroy(), so the later
> string_stream_clear() of suite->log in kunit_init_suite() will cause
> below UAF bug.
>
> Set stream pointer to NULL after free in string_stream_destroy()
> to fix it.
>
> Unable to handle kernel paging request at virtual address 006440150000030d
> Mem abort info:
> ESR = 0x0000000096000004
> EC = 0x25: DABT (current EL), IL = 32 bits
> SET = 0, FnV = 0
> EA = 0, S1PTW = 0
> FSC = 0x04: level 0 translation fault
> Data abort info:
> ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [006440150000030d] address between user and kernel address ranges
> Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> Dumping ftrace buffer:
> (ftrace buffer empty)
> Modules linked in: iio_test_gts industrialio_gts_helper cfg80211 rfkill ipv6 [last unloaded: iio_test_gts]
> CPU: 5 UID: 0 PID: 6253 Comm: modprobe Tainted: G B W N 6.12.0-rc4+ #458
> Tainted: [B]=BAD_PAGE, [W]=WARN, [N]=TEST
> Hardware name: linux,dummy-virt (DT)
> pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : string_stream_clear+0x54/0x1ac
> lr : string_stream_clear+0x1a8/0x1ac
> sp : ffffffc080b47410
> x29: ffffffc080b47410 x28: 006440550000030d x27: ffffff80c96b5e98
> x26: ffffff80c96b5e80 x25: ffffffe461b3f6c0 x24: 0000000000000003
> x23: ffffff80c96b5e88 x22: 1ffffff019cdf4fc x21: dfffffc000000000
> x20: ffffff80ce6fa7e0 x19: 032202a80000186d x18: 0000000000001840
> x17: 0000000000000000 x16: 0000000000000000 x15: ffffffe45c355cb4
> x14: ffffffe45c35589c x13: ffffffe45c03da78 x12: ffffffb810168e75
> x11: 1ffffff810168e74 x10: ffffffb810168e74 x9 : dfffffc000000000
> x8 : 0000000000000004 x7 : 0000000000000003 x6 : 0000000000000001
> x5 : ffffffc080b473a0 x4 : 0000000000000000 x3 : 0000000000000000
> x2 : 0000000000000001 x1 : ffffffe462fbf620 x0 : dfffffc000000000
> Call trace:
> string_stream_clear+0x54/0x1ac
> __kunit_test_suites_init+0x108/0x1d8
> kunit_exec_run_tests+0xb8/0x100
> kunit_module_notify+0x400/0x55c
> notifier_call_chain+0xfc/0x3b4
> blocking_notifier_call_chain+0x68/0x9c
> do_init_module+0x24c/0x5c8
> load_module+0x4acc/0x4e90
> init_module_from_file+0xd4/0x128
> idempotent_init_module+0x2d4/0x57c
> __arm64_sys_finit_module+0xac/0x100
> invoke_syscall+0x6c/0x258
> el0_svc_common.constprop.0+0x160/0x22c
> do_el0_svc+0x44/0x5c
> el0_svc+0x48/0xb8
> el0t_64_sync_handler+0x13c/0x158
> el0t_64_sync+0x190/0x194
> Code: f9400753 d2dff800 f2fbffe0 d343fe7c (38e06b80)
> ---[ end trace 0000000000000000 ]---
> Kernel panic - not syncing: Oops: Fatal exception
>
> Cc: stable@vger.kernel.org
> Fixes: a3fdf784780c ("kunit: string-stream: Decouple string_stream from kunit")
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> lib/kunit/string-stream.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
> index 54f4fdcbfac8..00ad518b730b 100644
> --- a/lib/kunit/string-stream.c
> +++ b/lib/kunit/string-stream.c
> @@ -178,6 +178,7 @@ void string_stream_destroy(struct string_stream *stream)
>
> string_stream_clear(stream);
> kfree(stream);
> + stream = NULL;
Thanks for proposing the fix. However, I don't believe it fully
resolves the UAF issue. Changing the stream pointer value within
string_stream_destroy() doesn't update the caller's stream pointer, so
the issue remains.
I think the correct approach would be to set the log pointer to NULL in
the error path of kunit_debugfs_create_suite() to address the issue.
Let me know if I've missed something or overlooked an obvious detail.
Here's the proposed code:
diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
index d548750a325a..b25d214b93e1 100644
--- a/lib/kunit/debugfs.c
+++ b/lib/kunit/debugfs.c
@@ -212,8 +212,11 @@ void kunit_debugfs_create_suite(struct kunit_suite *suite)
err:
string_stream_destroy(suite->log);
- kunit_suite_for_each_test_case(suite, test_case)
+ suite->log = NULL;
+ kunit_suite_for_each_test_case(suite, test_case) {
string_stream_destroy(test_case->log);
+ test_case->log = NULL;
+ }
}
void kunit_debugfs_destroy_suite(struct kunit_suite *suite)
> }
>
> static void resource_free_string_stream(void *p)
> --
> 2.34.1
>
>
On 2024/11/9 20:40, Kuan-Wei Chiu wrote:
> Hi Jinjie,
>
> On Thu, Oct 24, 2024 at 05:43:03PM +0800, Jinjie Ruan wrote:
>> In kunit_debugfs_create_suite(), if alloc_string_stream() fails in the
>> kunit_suite_for_each_test_case() loop, the "suite->log = stream"
>> has assigned before, and the error path only free the suite->log's stream
>> memory but not set it to NULL in string_stream_destroy(), so the later
>> string_stream_clear() of suite->log in kunit_init_suite() will cause
>> below UAF bug.
>>
>> Set stream pointer to NULL after free in string_stream_destroy()
>> to fix it.
>>
>> Unable to handle kernel paging request at virtual address 006440150000030d
>> Mem abort info:
>> ESR = 0x0000000096000004
>> EC = 0x25: DABT (current EL), IL = 32 bits
>> SET = 0, FnV = 0
>> EA = 0, S1PTW = 0
>> FSC = 0x04: level 0 translation fault
>> Data abort info:
>> ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
>> CM = 0, WnR = 0, TnD = 0, TagAccess = 0
>> GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>> [006440150000030d] address between user and kernel address ranges
>> Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
>> Dumping ftrace buffer:
>> (ftrace buffer empty)
>> Modules linked in: iio_test_gts industrialio_gts_helper cfg80211 rfkill ipv6 [last unloaded: iio_test_gts]
>> CPU: 5 UID: 0 PID: 6253 Comm: modprobe Tainted: G B W N 6.12.0-rc4+ #458
>> Tainted: [B]=BAD_PAGE, [W]=WARN, [N]=TEST
>> Hardware name: linux,dummy-virt (DT)
>> pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>> pc : string_stream_clear+0x54/0x1ac
>> lr : string_stream_clear+0x1a8/0x1ac
>> sp : ffffffc080b47410
>> x29: ffffffc080b47410 x28: 006440550000030d x27: ffffff80c96b5e98
>> x26: ffffff80c96b5e80 x25: ffffffe461b3f6c0 x24: 0000000000000003
>> x23: ffffff80c96b5e88 x22: 1ffffff019cdf4fc x21: dfffffc000000000
>> x20: ffffff80ce6fa7e0 x19: 032202a80000186d x18: 0000000000001840
>> x17: 0000000000000000 x16: 0000000000000000 x15: ffffffe45c355cb4
>> x14: ffffffe45c35589c x13: ffffffe45c03da78 x12: ffffffb810168e75
>> x11: 1ffffff810168e74 x10: ffffffb810168e74 x9 : dfffffc000000000
>> x8 : 0000000000000004 x7 : 0000000000000003 x6 : 0000000000000001
>> x5 : ffffffc080b473a0 x4 : 0000000000000000 x3 : 0000000000000000
>> x2 : 0000000000000001 x1 : ffffffe462fbf620 x0 : dfffffc000000000
>> Call trace:
>> string_stream_clear+0x54/0x1ac
>> __kunit_test_suites_init+0x108/0x1d8
>> kunit_exec_run_tests+0xb8/0x100
>> kunit_module_notify+0x400/0x55c
>> notifier_call_chain+0xfc/0x3b4
>> blocking_notifier_call_chain+0x68/0x9c
>> do_init_module+0x24c/0x5c8
>> load_module+0x4acc/0x4e90
>> init_module_from_file+0xd4/0x128
>> idempotent_init_module+0x2d4/0x57c
>> __arm64_sys_finit_module+0xac/0x100
>> invoke_syscall+0x6c/0x258
>> el0_svc_common.constprop.0+0x160/0x22c
>> do_el0_svc+0x44/0x5c
>> el0_svc+0x48/0xb8
>> el0t_64_sync_handler+0x13c/0x158
>> el0t_64_sync+0x190/0x194
>> Code: f9400753 d2dff800 f2fbffe0 d343fe7c (38e06b80)
>> ---[ end trace 0000000000000000 ]---
>> Kernel panic - not syncing: Oops: Fatal exception
>>
>> Cc: stable@vger.kernel.org
>> Fixes: a3fdf784780c ("kunit: string-stream: Decouple string_stream from kunit")
>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
>> ---
>> lib/kunit/string-stream.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
>> index 54f4fdcbfac8..00ad518b730b 100644
>> --- a/lib/kunit/string-stream.c
>> +++ b/lib/kunit/string-stream.c
>> @@ -178,6 +178,7 @@ void string_stream_destroy(struct string_stream *stream)
>>
>> string_stream_clear(stream);
>> kfree(stream);
>> + stream = NULL;
>
> Thanks for proposing the fix. However, I don't believe it fully
> resolves the UAF issue. Changing the stream pointer value within
> string_stream_destroy() doesn't update the caller's stream pointer, so
> the issue remains.
>
> I think the correct approach would be to set the log pointer to NULL in
> the error path of kunit_debugfs_create_suite() to address the issue.
> Let me know if I've missed something or overlooked an obvious detail.
>
> Here's the proposed code:
>
> diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
> index d548750a325a..b25d214b93e1 100644
> --- a/lib/kunit/debugfs.c
> +++ b/lib/kunit/debugfs.c
> @@ -212,8 +212,11 @@ void kunit_debugfs_create_suite(struct kunit_suite *suite)
>
> err:
> string_stream_destroy(suite->log);
> - kunit_suite_for_each_test_case(suite, test_case)
> + suite->log = NULL;
> + kunit_suite_for_each_test_case(suite, test_case) {
> string_stream_destroy(test_case->log);
> + test_case->log = NULL;
> + }
It looks fine, test it and if ok, will update it.
> }
>
> void kunit_debugfs_destroy_suite(struct kunit_suite *suite)
>
>
>> }
>>
>> static void resource_free_string_stream(void *p)
>> --
>> 2.34.1
>>
>>
On Sat, Nov 09, 2024 at 08:40:30PM +0800, Kuan-Wei Chiu wrote:
> Hi Jinjie,
>
> On Thu, Oct 24, 2024 at 05:43:03PM +0800, Jinjie Ruan wrote:
> > In kunit_debugfs_create_suite(), if alloc_string_stream() fails in the
> > kunit_suite_for_each_test_case() loop, the "suite->log = stream"
> > has assigned before, and the error path only free the suite->log's stream
> > memory but not set it to NULL in string_stream_destroy(), so the later
> > string_stream_clear() of suite->log in kunit_init_suite() will cause
> > below UAF bug.
> >
> > Set stream pointer to NULL after free in string_stream_destroy()
> > to fix it.
> >
> > Unable to handle kernel paging request at virtual address 006440150000030d
> > Mem abort info:
> > ESR = 0x0000000096000004
> > EC = 0x25: DABT (current EL), IL = 32 bits
> > SET = 0, FnV = 0
> > EA = 0, S1PTW = 0
> > FSC = 0x04: level 0 translation fault
> > Data abort info:
> > ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> > CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> > GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> > [006440150000030d] address between user and kernel address ranges
> > Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> > Dumping ftrace buffer:
> > (ftrace buffer empty)
> > Modules linked in: iio_test_gts industrialio_gts_helper cfg80211 rfkill ipv6 [last unloaded: iio_test_gts]
> > CPU: 5 UID: 0 PID: 6253 Comm: modprobe Tainted: G B W N 6.12.0-rc4+ #458
> > Tainted: [B]=BAD_PAGE, [W]=WARN, [N]=TEST
> > Hardware name: linux,dummy-virt (DT)
> > pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > pc : string_stream_clear+0x54/0x1ac
> > lr : string_stream_clear+0x1a8/0x1ac
> > sp : ffffffc080b47410
> > x29: ffffffc080b47410 x28: 006440550000030d x27: ffffff80c96b5e98
> > x26: ffffff80c96b5e80 x25: ffffffe461b3f6c0 x24: 0000000000000003
> > x23: ffffff80c96b5e88 x22: 1ffffff019cdf4fc x21: dfffffc000000000
> > x20: ffffff80ce6fa7e0 x19: 032202a80000186d x18: 0000000000001840
> > x17: 0000000000000000 x16: 0000000000000000 x15: ffffffe45c355cb4
> > x14: ffffffe45c35589c x13: ffffffe45c03da78 x12: ffffffb810168e75
> > x11: 1ffffff810168e74 x10: ffffffb810168e74 x9 : dfffffc000000000
> > x8 : 0000000000000004 x7 : 0000000000000003 x6 : 0000000000000001
> > x5 : ffffffc080b473a0 x4 : 0000000000000000 x3 : 0000000000000000
> > x2 : 0000000000000001 x1 : ffffffe462fbf620 x0 : dfffffc000000000
> > Call trace:
> > string_stream_clear+0x54/0x1ac
> > __kunit_test_suites_init+0x108/0x1d8
> > kunit_exec_run_tests+0xb8/0x100
> > kunit_module_notify+0x400/0x55c
> > notifier_call_chain+0xfc/0x3b4
> > blocking_notifier_call_chain+0x68/0x9c
> > do_init_module+0x24c/0x5c8
> > load_module+0x4acc/0x4e90
> > init_module_from_file+0xd4/0x128
> > idempotent_init_module+0x2d4/0x57c
> > __arm64_sys_finit_module+0xac/0x100
> > invoke_syscall+0x6c/0x258
> > el0_svc_common.constprop.0+0x160/0x22c
> > do_el0_svc+0x44/0x5c
> > el0_svc+0x48/0xb8
> > el0t_64_sync_handler+0x13c/0x158
> > el0t_64_sync+0x190/0x194
> > Code: f9400753 d2dff800 f2fbffe0 d343fe7c (38e06b80)
> > ---[ end trace 0000000000000000 ]---
> > Kernel panic - not syncing: Oops: Fatal exception
> >
> > Cc: stable@vger.kernel.org
> > Fixes: a3fdf784780c ("kunit: string-stream: Decouple string_stream from kunit")
> > Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> > ---
> > lib/kunit/string-stream.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
> > index 54f4fdcbfac8..00ad518b730b 100644
> > --- a/lib/kunit/string-stream.c
> > +++ b/lib/kunit/string-stream.c
> > @@ -178,6 +178,7 @@ void string_stream_destroy(struct string_stream *stream)
> >
> > string_stream_clear(stream);
> > kfree(stream);
> > + stream = NULL;
>
> Thanks for proposing the fix. However, I don't believe it fully
> resolves the UAF issue. Changing the stream pointer value within
> string_stream_destroy() doesn't update the caller's stream pointer, so
> the issue remains.
>
> I think the correct approach would be to set the log pointer to NULL in
> the error path of kunit_debugfs_create_suite() to address the issue.
> Let me know if I've missed something or overlooked an obvious detail.
>
BTW, since alloc_string_stream() returns -ENOMEM on error rather than
NULL, it's best for the caller to check it with IS_ERR() instead of
IS_ERR_OR_NULL(). It's not a big issue, but I can send a cleanup patch
later to address this.
Regards,
Kuan-Wei
On 2024/11/9 21:02, Kuan-Wei Chiu wrote:
> On Sat, Nov 09, 2024 at 08:40:30PM +0800, Kuan-Wei Chiu wrote:
>> Hi Jinjie,
>>
>> On Thu, Oct 24, 2024 at 05:43:03PM +0800, Jinjie Ruan wrote:
>>> In kunit_debugfs_create_suite(), if alloc_string_stream() fails in the
>>> kunit_suite_for_each_test_case() loop, the "suite->log = stream"
>>> has assigned before, and the error path only free the suite->log's stream
>>> memory but not set it to NULL in string_stream_destroy(), so the later
>>> string_stream_clear() of suite->log in kunit_init_suite() will cause
>>> below UAF bug.
>>>
>>> Set stream pointer to NULL after free in string_stream_destroy()
>>> to fix it.
>>>
>>> Unable to handle kernel paging request at virtual address 006440150000030d
>>> Mem abort info:
>>> ESR = 0x0000000096000004
>>> EC = 0x25: DABT (current EL), IL = 32 bits
>>> SET = 0, FnV = 0
>>> EA = 0, S1PTW = 0
>>> FSC = 0x04: level 0 translation fault
>>> Data abort info:
>>> ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
>>> CM = 0, WnR = 0, TnD = 0, TagAccess = 0
>>> GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>>> [006440150000030d] address between user and kernel address ranges
>>> Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
>>> Dumping ftrace buffer:
>>> (ftrace buffer empty)
>>> Modules linked in: iio_test_gts industrialio_gts_helper cfg80211 rfkill ipv6 [last unloaded: iio_test_gts]
>>> CPU: 5 UID: 0 PID: 6253 Comm: modprobe Tainted: G B W N 6.12.0-rc4+ #458
>>> Tainted: [B]=BAD_PAGE, [W]=WARN, [N]=TEST
>>> Hardware name: linux,dummy-virt (DT)
>>> pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>> pc : string_stream_clear+0x54/0x1ac
>>> lr : string_stream_clear+0x1a8/0x1ac
>>> sp : ffffffc080b47410
>>> x29: ffffffc080b47410 x28: 006440550000030d x27: ffffff80c96b5e98
>>> x26: ffffff80c96b5e80 x25: ffffffe461b3f6c0 x24: 0000000000000003
>>> x23: ffffff80c96b5e88 x22: 1ffffff019cdf4fc x21: dfffffc000000000
>>> x20: ffffff80ce6fa7e0 x19: 032202a80000186d x18: 0000000000001840
>>> x17: 0000000000000000 x16: 0000000000000000 x15: ffffffe45c355cb4
>>> x14: ffffffe45c35589c x13: ffffffe45c03da78 x12: ffffffb810168e75
>>> x11: 1ffffff810168e74 x10: ffffffb810168e74 x9 : dfffffc000000000
>>> x8 : 0000000000000004 x7 : 0000000000000003 x6 : 0000000000000001
>>> x5 : ffffffc080b473a0 x4 : 0000000000000000 x3 : 0000000000000000
>>> x2 : 0000000000000001 x1 : ffffffe462fbf620 x0 : dfffffc000000000
>>> Call trace:
>>> string_stream_clear+0x54/0x1ac
>>> __kunit_test_suites_init+0x108/0x1d8
>>> kunit_exec_run_tests+0xb8/0x100
>>> kunit_module_notify+0x400/0x55c
>>> notifier_call_chain+0xfc/0x3b4
>>> blocking_notifier_call_chain+0x68/0x9c
>>> do_init_module+0x24c/0x5c8
>>> load_module+0x4acc/0x4e90
>>> init_module_from_file+0xd4/0x128
>>> idempotent_init_module+0x2d4/0x57c
>>> __arm64_sys_finit_module+0xac/0x100
>>> invoke_syscall+0x6c/0x258
>>> el0_svc_common.constprop.0+0x160/0x22c
>>> do_el0_svc+0x44/0x5c
>>> el0_svc+0x48/0xb8
>>> el0t_64_sync_handler+0x13c/0x158
>>> el0t_64_sync+0x190/0x194
>>> Code: f9400753 d2dff800 f2fbffe0 d343fe7c (38e06b80)
>>> ---[ end trace 0000000000000000 ]---
>>> Kernel panic - not syncing: Oops: Fatal exception
>>>
>>> Cc: stable@vger.kernel.org
>>> Fixes: a3fdf784780c ("kunit: string-stream: Decouple string_stream from kunit")
>>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
>>> ---
>>> lib/kunit/string-stream.c | 1 +
>>> 1 file changed, 1 insertion(+)
>>>
>>> diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
>>> index 54f4fdcbfac8..00ad518b730b 100644
>>> --- a/lib/kunit/string-stream.c
>>> +++ b/lib/kunit/string-stream.c
>>> @@ -178,6 +178,7 @@ void string_stream_destroy(struct string_stream *stream)
>>>
>>> string_stream_clear(stream);
>>> kfree(stream);
>>> + stream = NULL;
>>
>> Thanks for proposing the fix. However, I don't believe it fully
>> resolves the UAF issue. Changing the stream pointer value within
>> string_stream_destroy() doesn't update the caller's stream pointer, so
>> the issue remains.
>>
>> I think the correct approach would be to set the log pointer to NULL in
>> the error path of kunit_debugfs_create_suite() to address the issue.
>> Let me know if I've missed something or overlooked an obvious detail.
>>
> BTW, since alloc_string_stream() returns -ENOMEM on error rather than
> NULL, it's best for the caller to check it with IS_ERR() instead of
> IS_ERR_OR_NULL(). It's not a big issue, but I can send a cleanup patch
> later to address this.
Yes, I also notice it, but It's not a big issue. Thank you very much!
>
> Regards,
> Kuan-Wei
On Thu, 24 Oct 2024 at 17:43, Jinjie Ruan <ruanjinjie@huawei.com> wrote:
>
> In kunit_debugfs_create_suite(), if alloc_string_stream() fails in the
> kunit_suite_for_each_test_case() loop, the "suite->log = stream"
> has assigned before, and the error path only free the suite->log's stream
> memory but not set it to NULL in string_stream_destroy(), so the later
> string_stream_clear() of suite->log in kunit_init_suite() will cause
> below UAF bug.
>
> Set stream pointer to NULL after free in string_stream_destroy()
> to fix it.
>
> Unable to handle kernel paging request at virtual address 006440150000030d
> Mem abort info:
> ESR = 0x0000000096000004
> EC = 0x25: DABT (current EL), IL = 32 bits
> SET = 0, FnV = 0
> EA = 0, S1PTW = 0
> FSC = 0x04: level 0 translation fault
> Data abort info:
> ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [006440150000030d] address between user and kernel address ranges
> Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> Dumping ftrace buffer:
> (ftrace buffer empty)
> Modules linked in: iio_test_gts industrialio_gts_helper cfg80211 rfkill ipv6 [last unloaded: iio_test_gts]
> CPU: 5 UID: 0 PID: 6253 Comm: modprobe Tainted: G B W N 6.12.0-rc4+ #458
> Tainted: [B]=BAD_PAGE, [W]=WARN, [N]=TEST
> Hardware name: linux,dummy-virt (DT)
> pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : string_stream_clear+0x54/0x1ac
> lr : string_stream_clear+0x1a8/0x1ac
> sp : ffffffc080b47410
> x29: ffffffc080b47410 x28: 006440550000030d x27: ffffff80c96b5e98
> x26: ffffff80c96b5e80 x25: ffffffe461b3f6c0 x24: 0000000000000003
> x23: ffffff80c96b5e88 x22: 1ffffff019cdf4fc x21: dfffffc000000000
> x20: ffffff80ce6fa7e0 x19: 032202a80000186d x18: 0000000000001840
> x17: 0000000000000000 x16: 0000000000000000 x15: ffffffe45c355cb4
> x14: ffffffe45c35589c x13: ffffffe45c03da78 x12: ffffffb810168e75
> x11: 1ffffff810168e74 x10: ffffffb810168e74 x9 : dfffffc000000000
> x8 : 0000000000000004 x7 : 0000000000000003 x6 : 0000000000000001
> x5 : ffffffc080b473a0 x4 : 0000000000000000 x3 : 0000000000000000
> x2 : 0000000000000001 x1 : ffffffe462fbf620 x0 : dfffffc000000000
> Call trace:
> string_stream_clear+0x54/0x1ac
> __kunit_test_suites_init+0x108/0x1d8
> kunit_exec_run_tests+0xb8/0x100
> kunit_module_notify+0x400/0x55c
> notifier_call_chain+0xfc/0x3b4
> blocking_notifier_call_chain+0x68/0x9c
> do_init_module+0x24c/0x5c8
> load_module+0x4acc/0x4e90
> init_module_from_file+0xd4/0x128
> idempotent_init_module+0x2d4/0x57c
> __arm64_sys_finit_module+0xac/0x100
> invoke_syscall+0x6c/0x258
> el0_svc_common.constprop.0+0x160/0x22c
> do_el0_svc+0x44/0x5c
> el0_svc+0x48/0xb8
> el0t_64_sync_handler+0x13c/0x158
> el0t_64_sync+0x190/0x194
> Code: f9400753 d2dff800 f2fbffe0 d343fe7c (38e06b80)
> ---[ end trace 0000000000000000 ]---
> Kernel panic - not syncing: Oops: Fatal exception
>
> Cc: stable@vger.kernel.org
> Fixes: a3fdf784780c ("kunit: string-stream: Decouple string_stream from kunit")
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
Nice catch, thanks.
Reviewed-by: David Gow <davidgow@google.com>
Cheers,
-- David
> lib/kunit/string-stream.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
> index 54f4fdcbfac8..00ad518b730b 100644
> --- a/lib/kunit/string-stream.c
> +++ b/lib/kunit/string-stream.c
> @@ -178,6 +178,7 @@ void string_stream_destroy(struct string_stream *stream)
>
> string_stream_clear(stream);
> kfree(stream);
> + stream = NULL;
> }
>
> static void resource_free_string_stream(void *p)
> --
> 2.34.1
>
Gentle Ping.
On 2024/10/24 17:43, Jinjie Ruan wrote:
> In kunit_debugfs_create_suite(), if alloc_string_stream() fails in the
> kunit_suite_for_each_test_case() loop, the "suite->log = stream"
> has assigned before, and the error path only free the suite->log's stream
> memory but not set it to NULL in string_stream_destroy(), so the later
> string_stream_clear() of suite->log in kunit_init_suite() will cause
> below UAF bug.
>
> Set stream pointer to NULL after free in string_stream_destroy()
> to fix it.
>
> Unable to handle kernel paging request at virtual address 006440150000030d
> Mem abort info:
> ESR = 0x0000000096000004
> EC = 0x25: DABT (current EL), IL = 32 bits
> SET = 0, FnV = 0
> EA = 0, S1PTW = 0
> FSC = 0x04: level 0 translation fault
> Data abort info:
> ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
> CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [006440150000030d] address between user and kernel address ranges
> Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
> Dumping ftrace buffer:
> (ftrace buffer empty)
> Modules linked in: iio_test_gts industrialio_gts_helper cfg80211 rfkill ipv6 [last unloaded: iio_test_gts]
> CPU: 5 UID: 0 PID: 6253 Comm: modprobe Tainted: G B W N 6.12.0-rc4+ #458
> Tainted: [B]=BAD_PAGE, [W]=WARN, [N]=TEST
> Hardware name: linux,dummy-virt (DT)
> pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : string_stream_clear+0x54/0x1ac
> lr : string_stream_clear+0x1a8/0x1ac
> sp : ffffffc080b47410
> x29: ffffffc080b47410 x28: 006440550000030d x27: ffffff80c96b5e98
> x26: ffffff80c96b5e80 x25: ffffffe461b3f6c0 x24: 0000000000000003
> x23: ffffff80c96b5e88 x22: 1ffffff019cdf4fc x21: dfffffc000000000
> x20: ffffff80ce6fa7e0 x19: 032202a80000186d x18: 0000000000001840
> x17: 0000000000000000 x16: 0000000000000000 x15: ffffffe45c355cb4
> x14: ffffffe45c35589c x13: ffffffe45c03da78 x12: ffffffb810168e75
> x11: 1ffffff810168e74 x10: ffffffb810168e74 x9 : dfffffc000000000
> x8 : 0000000000000004 x7 : 0000000000000003 x6 : 0000000000000001
> x5 : ffffffc080b473a0 x4 : 0000000000000000 x3 : 0000000000000000
> x2 : 0000000000000001 x1 : ffffffe462fbf620 x0 : dfffffc000000000
> Call trace:
> string_stream_clear+0x54/0x1ac
> __kunit_test_suites_init+0x108/0x1d8
> kunit_exec_run_tests+0xb8/0x100
> kunit_module_notify+0x400/0x55c
> notifier_call_chain+0xfc/0x3b4
> blocking_notifier_call_chain+0x68/0x9c
> do_init_module+0x24c/0x5c8
> load_module+0x4acc/0x4e90
> init_module_from_file+0xd4/0x128
> idempotent_init_module+0x2d4/0x57c
> __arm64_sys_finit_module+0xac/0x100
> invoke_syscall+0x6c/0x258
> el0_svc_common.constprop.0+0x160/0x22c
> do_el0_svc+0x44/0x5c
> el0_svc+0x48/0xb8
> el0t_64_sync_handler+0x13c/0x158
> el0t_64_sync+0x190/0x194
> Code: f9400753 d2dff800 f2fbffe0 d343fe7c (38e06b80)
> ---[ end trace 0000000000000000 ]---
> Kernel panic - not syncing: Oops: Fatal exception
>
> Cc: stable@vger.kernel.org
> Fixes: a3fdf784780c ("kunit: string-stream: Decouple string_stream from kunit")
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> lib/kunit/string-stream.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
> index 54f4fdcbfac8..00ad518b730b 100644
> --- a/lib/kunit/string-stream.c
> +++ b/lib/kunit/string-stream.c
> @@ -178,6 +178,7 @@ void string_stream_destroy(struct string_stream *stream)
>
> string_stream_clear(stream);
> kfree(stream);
> + stream = NULL;
> }
>
> static void resource_free_string_stream(void *p)
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