6.16-stable review patch. If anyone has any objections, please let me know.
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From: Yeoreum Yun yeoreum.yun@arm.com
commit 7a19afee6fb39df63ddea7ce78976d8c521178c6 upstream.
Similar to commit 09c6304e38e4 ("kasan: test: fix compatibility with FORTIFY_SOURCE") the kernel is panicing in kasan_string().
This is due to the `src` and `ptr` not being hidden from the optimizer which would disable the runtime fortify string checker.
Call trace: __fortify_panic+0x10/0x20 (P) kasan_strings+0x980/0x9b0 kunit_try_run_case+0x68/0x190 kunit_generic_run_threadfn_adapter+0x34/0x68 kthread+0x1c4/0x228 ret_from_fork+0x10/0x20 Code: d503233f a9bf7bfd 910003fd 9424b243 (d4210000) ---[ end trace 0000000000000000 ]--- note: kunit_try_catch[128] exited with irqs disabled note: kunit_try_catch[128] exited with preempt_count 1 # kasan_strings: try faulted: last ** replaying previous printk message ** # kasan_strings: try faulted: last line seen mm/kasan/kasan_test_c.c:1600 # kasan_strings: internal error occurred preventing test case from running: -4
Link: https://lkml.kernel.org/r/20250801120236.2962642-1-yeoreum.yun@arm.com Fixes: 73228c7ecc5e ("KASAN: port KASAN Tests to KUnit") Signed-off-by: Yeoreum Yun yeoreum.yun@arm.com Cc: Alexander Potapenko glider@google.com Cc: Andrey Konovalov andreyknvl@gmail.com Cc: Andrey Ryabinin ryabinin.a.a@gmail.com Cc: Dmitriy Vyukov dvyukov@google.com Cc: Vincenzo Frascino vincenzo.frascino@arm.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/kasan/kasan_test_c.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/mm/kasan/kasan_test_c.c +++ b/mm/kasan/kasan_test_c.c @@ -1578,9 +1578,11 @@ static void kasan_strings(struct kunit *
ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); + OPTIMIZER_HIDE_VAR(ptr);
src = kmalloc(KASAN_GRANULE_SIZE, GFP_KERNEL | __GFP_ZERO); strscpy(src, "f0cacc1a0000000", KASAN_GRANULE_SIZE); + OPTIMIZER_HIDE_VAR(src);
/* * Make sure that strscpy() does not trigger KASAN if it overreads into