lkml.org 
[lkml]   [2024]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [syzbot] [net?] [virt?] [kvm?] KASAN: slab-use-after-free Read in vhost_task_fn
    From
    Hello,

    syzbot has tested the proposed patch but the reproducer is still triggering an issue:
    WARNING: suspicious RCU usage in __do_softirq

    =============================
    WARNING: suspicious RCU usage
    6.9.0-rc5-next-20240426-syzkaller-dirty #0 Not tainted
    -----------------------------
    kernel/rcu/tree.c:276 Illegal rcu_softirq_qs() in RCU read-side critical section!

    other info that might help us debug this:


    rcu_scheduler_active = 2, debug_locks = 1
    1 lock held by ksoftirqd/0/16:
    #0: ffffffff8e333b20 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
    #0: ffffffff8e333b20 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:933 [inline]
    #0: ffffffff8e333b20 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid include/linux/mmzone.h:2022 [inline]
    #0: ffffffff8e333b20 (rcu_read_lock_sched){....}-{1:2}, at: __virt_addr_valid+0x183/0x520 arch/x86/mm/physaddr.c:65

    stack backtrace:
    CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.9.0-rc5-next-20240426-syzkaller-dirty #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
    Call Trace:
    <IRQ>
    __dump_stack lib/dump_stack.c:88 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
    lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712
    rcu_softirq_qs+0xd9/0x370 kernel/rcu/tree.c:273
    __do_softirq+0x5fd/0x980 kernel/softirq.c:568
    invoke_softirq kernel/softirq.c:428 [inline]
    __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
    irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
    instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
    sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
    </IRQ>
    <TASK>
    asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
    RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758
    Code: 2b 00 74 08 4c 89 f7 e8 aa 61 89 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
    RSP: 0018:ffffc900001578e0 EFLAGS: 00000206
    RAX: 0000000000000001 RBX: 1ffff9200002af28 RCX: 0000000000000001
    RDX: dffffc0000000000 RSI: ffffffff8bcac4c0 RDI: ffffffff8c1fc4e0
    RBP: ffffc90000157a40 R08: ffffffff92f96587 R09: 1ffffffff25f2cb0
    R10: dffffc0000000000 R11: fffffbfff25f2cb1 R12: 1ffff9200002af24
    R13: dffffc0000000000 R14: ffffc90000157940 R15: 0000000000000246
    rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
    rcu_read_lock_sched include/linux/rcupdate.h:933 [inline]
    pfn_valid include/linux/mmzone.h:2022 [inline]
    __virt_addr_valid+0x1a0/0x520 arch/x86/mm/physaddr.c:65
    kasan_addr_to_slab+0xd/0x80 mm/kasan/common.c:37
    __kasan_record_aux_stack+0x11/0xc0 mm/kasan/generic.c:526
    __call_rcu_common kernel/rcu/tree.c:3103 [inline]
    call_rcu+0x167/0xa70 kernel/rcu/tree.c:3207
    context_switch kernel/sched/core.c:5411 [inline]
    __schedule+0x17f0/0x4a50 kernel/sched/core.c:6745
    __schedule_loop kernel/sched/core.c:6822 [inline]
    schedule+0x14b/0x320 kernel/sched/core.c:6837
    smpboot_thread_fn+0x61e/0xa30 kernel/smpboot.c:160
    kthread+0x2f0/0x390 kernel/kthread.c:389
    ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
    </TASK>
    ----------------
    Code disassembly (best guess):
    0: 2b 00 sub (%rax),%eax
    2: 74 08 je 0xc
    4: 4c 89 f7 mov %r14,%rdi
    7: e8 aa 61 89 00 call 0x8961b6
    c: f6 44 24 61 02 testb $0x2,0x61(%rsp)
    11: 0f 85 85 01 00 00 jne 0x19c
    17: 41 f7 c7 00 02 00 00 test $0x200,%r15d
    1e: 74 01 je 0x21
    20: fb sti
    21: 48 c7 44 24 40 0e 36 movq $0x45e0360e,0x40(%rsp)
    28: e0 45
    * 2a: 4b c7 44 25 00 00 00 movq $0x0,0x0(%r13,%r12,1) <-- trapping instruction
    31: 00 00
    33: 43 c7 44 25 09 00 00 movl $0x0,0x9(%r13,%r12,1)
    3a: 00 00
    3c: 43 rex.XB
    3d: c7 .byte 0xc7
    3e: 44 rex.R
    3f: 25 .byte 0x25


    Tested on:

    commit: bb7a2467 Add linux-next specific files for 20240426
    git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
    console output: https://syzkaller.appspot.com/x/log.txt?x=11b1a228980000
    kernel config: https://syzkaller.appspot.com/x/.config?x=5c6a0288262dd108
    dashboard link: https://syzkaller.appspot.com/bug?extid=98edc2df894917b3431f
    compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
    patch: https://syzkaller.appspot.com/x/patch.diff?x=16d4837f180000


    \
     
     \ /
      Last update: 2024-05-27 18:09    [W:2.525 / U:0.112 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site