From: syzbot <syzbot+331f5bebb641724ff1f0@syzkaller.appspotmail.com>
To: andrii@kernel.org, arighi@nvidia.com, ast@kernel.org,
bpf@vger.kernel.org, bsegall@google.com, changwoo@igalia.com,
daniel@iogearbox.net, dietmar.eggemann@arm.com,
eddyz87@gmail.com, haoluo@google.com, john.fastabend@gmail.com,
jolsa@kernel.org, juri.lelli@redhat.com, kpsingh@kernel.org,
linux-kernel@vger.kernel.org, martin.lau@linux.dev,
mgorman@suse.de, mingo@redhat.com, netdev@vger.kernel.org,
peterz@infradead.org, rostedt@goodmis.org,
sched-ext@lists.linux.dev, sdf@fomichev.me, song@kernel.org,
syzkaller-bugs@googlegroups.com, tj@kernel.org,
vincent.guittot@linaro.org, void@manifault.com,
vschneid@redhat.com, yonghong.song@linux.dev
Subject: [syzbot] [bpf?] general protection fault in __pcpu_freelist_pop
Date: Mon, 18 Aug 2025 00:53:33 -0700 [thread overview]
Message-ID: <68a2dbfd.050a0220.e29e5.0094.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: e4414b01c1cd bpf: Check the helper function is valid in ge..
git tree: bpf
console output: https://syzkaller.appspot.com/x/log.txt?x=11cd4442580000
kernel config: https://syzkaller.appspot.com/x/.config?x=412ee2f8b704a5e6
dashboard link: https://syzkaller.appspot.com/bug?extid=331f5bebb641724ff1f0
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10d2e3a2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11bd0ba2580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/cf622f58cf3e/disk-e4414b01.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8947767e2701/vmlinux-e4414b01.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2a73aee74e9c/bzImage-e4414b01.xz
The issue was bisected to:
commit c68ea8243c5cc901cea62f695504bec73195d906
Author: Andrea Righi <arighi@nvidia.com>
Date: Wed Jun 4 14:33:11 2025 +0000
sched_ext: idle: Remove unnecessary ifdef in scx_bpf_cpu_node()
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13d7aba2580000
final oops: https://syzkaller.appspot.com/x/report.txt?x=1037aba2580000
console output: https://syzkaller.appspot.com/x/log.txt?x=17d7aba2580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+331f5bebb641724ff1f0@syzkaller.appspotmail.com
Fixes: c68ea8243c5c ("sched_ext: idle: Remove unnecessary ifdef in scx_bpf_cpu_node()")
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 5867 Comm: syz-executor Not tainted 6.17.0-rc1-syzkaller-ge4414b01c1cd #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:___pcpu_freelist_pop kernel/bpf/percpu_freelist.c:114 [inline]
RIP: 0010:__pcpu_freelist_pop+0x6b7/0x8c0 kernel/bpf/percpu_freelist.c:125
Code: 10 48 3b 8c 24 80 00 00 00 0f 85 b4 01 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 89 f8 48 c1 e8 03 <80> 3c 18 00 48 89 7c 24 20 74 0a e8 29 3f 41 00 48 8b 7c 24 20 48
RSP: 0018:ffffc90000a08820 EFLAGS: 00010046
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffe8ffffd6e308
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90000a088f0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141110 R12: 1ffffd1ffffadc60
R13: ffffe8ffffd6e300 R14: 0000000000000001 R15: 0000000000000000
FS: 0000555583dc4500(0000) GS:ffff888125d1c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555622ed5c8 CR3: 00000000769d6000 CR4: 00000000003526f0
Call Trace:
<IRQ>
pcpu_freelist_pop+0xca/0x170 kernel/bpf/percpu_freelist.c:134
__bpf_get_stackid+0x574/0xcf0 kernel/bpf/stackmap.c:259
____bpf_get_stackid_raw_tp kernel/trace/bpf_trace.c:1810 [inline]
bpf_get_stackid_raw_tp+0x196/0x210 kernel/trace/bpf_trace.c:1799
bpf_prog_b724608cae728045+0x27/0x2f
bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline]
__bpf_prog_run include/linux/filter.h:718 [inline]
bpf_prog_run include/linux/filter.h:725 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2257 [inline]
bpf_trace_run2+0x284/0x4b0 kernel/trace/bpf_trace.c:2298
__do_trace_kfree include/trace/events/kmem.h:94 [inline]
trace_kfree include/trace/events/kmem.h:94 [inline]
kfree+0x3a0/0x440 mm/slub.c:4866
slab_free_after_rcu_debug+0x60/0x2a0 mm/slub.c:4717
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0xca8/0x1770 kernel/rcu/tree.c:2861
handle_softirqs+0x283/0x870 kernel/softirq.c:579
do_softirq+0xec/0x180 kernel/softirq.c:480
</IRQ>
<TASK>
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
lock_sock include/net/sock.h:1667 [inline]
tcp_sendmsg+0x21/0x50 net/ipv4/tcp.c:1392
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x19c/0x270 net/socket.c:729
sock_write_iter+0x258/0x330 net/socket.c:1179
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe78c18d660
Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 01 af 1f 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007ffc45dccfb8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000179a7b00 RCX: 00007fe78c18d660
RDX: 0000000000000108 RSI: 00007fe789c3fef8 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000007 R09: 000000000003fde8
R10: 1a917aa2f8ade145 R11: 0000000000000202 R12: 0000000000000108
R13: 0000555583ddd6d0 R14: 00007ffc45dcd480 R15: 00007fe789c3fef8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:___pcpu_freelist_pop kernel/bpf/percpu_freelist.c:114 [inline]
RIP: 0010:__pcpu_freelist_pop+0x6b7/0x8c0 kernel/bpf/percpu_freelist.c:125
Code: 10 48 3b 8c 24 80 00 00 00 0f 85 b4 01 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 89 f8 48 c1 e8 03 <80> 3c 18 00 48 89 7c 24 20 74 0a e8 29 3f 41 00 48 8b 7c 24 20 48
RSP: 0018:ffffc90000a08820 EFLAGS: 00010046
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffe8ffffd6e308
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc90000a088f0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141110 R12: 1ffffd1ffffadc60
R13: ffffe8ffffd6e300 R14: 0000000000000001 R15: 0000000000000000
FS: 0000555583dc4500(0000) GS:ffff888125d1c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555622ed5c8 CR3: 00000000769d6000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 10 48 3b adc %cl,0x3b(%rax)
3: 8c 24 80 mov %fs,(%rax,%rax,4)
6: 00 00 add %al,(%rax)
8: 00 0f add %cl,(%rdi)
a: 85 b4 01 00 00 48 8d test %esi,-0x72b80000(%rcx,%rax,1)
11: 65 d8 5b 41 fcomps %gs:0x41(%rbx)
15: 5c pop %rsp
16: 41 5d pop %r13
18: 41 5e pop %r14
1a: 41 5f pop %r15
1c: 5d pop %rbp
1d: c3 ret
1e: cc int3
1f: cc int3
20: cc int3
21: cc int3
22: cc int3
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) <-- trapping instruction
2e: 48 89 7c 24 20 mov %rdi,0x20(%rsp)
33: 74 0a je 0x3f
35: e8 29 3f 41 00 call 0x413f63
3a: 48 8b 7c 24 20 mov 0x20(%rsp),%rdi
3f: 48 rex.W
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
If the report is already addressed, let syzbot know by replying with:
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reply other threads:[~2025-08-18 7:53 UTC|newest]
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