| Message ID | 20241024094303.1531810-1-ruanjinjie@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Brendan Higgins |
| Headers | show |
| Series | kunit: string-stream: Fix a UAF bug in kunit_init_suite() | expand |
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)
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 >
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; + } } 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 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 >> >>
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)
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(+)