KASAN: out-of-bounds Read in perf_assign_events

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: c578ddb3 Merge tag 'linux-kselftest-5.7-rc3' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11c09ca0100000
kernel config: https://syzkaller.appspot.com/x/.config?x=78a7d8adda44b4b
dashboard link: https://syzkaller.appspot.com/bug?extid=d8f8bd5ce70ffd4f605a
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
CC: [ac...@kernel.org alexander...@linux.intel.com b...@alien8.de h...@zytor.com jo...@redhat.com linux-...@vger.kernel.org mark.r...@arm.com mi...@redhat.com namh...@kernel.org pet...@infradead.org tg...@linutronix.de x...@kernel.org]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d8f8bd...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: out-of-bounds in __perf_sched_find_counter arch/x86/events/core.c:784 [inline]
BUG: KASAN: out-of-bounds in perf_sched_find_counter arch/x86/events/core.c:833 [inline]
BUG: KASAN: out-of-bounds in perf_assign_events+0xb94/0x1040 arch/x86/events/core.c:881
Read of size 4 at addr ffffc90000f57fcc by task syz-fuzzer/7014

CPU: 1 PID: 7014 Comm: syz-fuzzer Not tainted 5.7.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1e9/0x30e lib/dump_stack.c:118
print_address_description+0x74/0x5c0 mm/kasan/report.c:382
__kasan_report+0x103/0x1a0 mm/kasan/report.c:511
kasan_report+0x4d/0x80 mm/kasan/common.c:625


Memory state around the buggy address:
ffffc90000f57e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc90000f57f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90000f57f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffffc90000f58000: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
ffffc90000f58080: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 7014 Comm: syz-fuzzer Tainted: G B 5.7.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1e9/0x30e lib/dump_stack.c:118
panic+0x264/0x7a0 kernel/panic.c:221
end_report mm/kasan/report.c:103 [inline]
__kasan_report+0x191/0x1a0 mm/kasan/report.c:518
kasan_report+0x4d/0x80 mm/kasan/common.c:625
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.