Re: [syzbot] [bpf?] [net?] general protection fault in __dev_flush

From: syzbot
Date: Wed Jul 24 2024 - 08:20:12 EST

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Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: stack-out-of-bounds Read in xdp_do_check_flushed

==================================================================
BUG: KASAN: stack-out-of-bounds in bpf_net_ctx_get_all_used_flush_lists include/linux/filter.h:837 [inline]
BUG: KASAN: stack-out-of-bounds in xdp_do_check_flushed+0x41c/0x4e0 net/core/filter.c:4298
Read of size 4 at addr ffffc900032bfa50 by task syz.0.42/5811

CPU: 0 UID: 0 PID: 5811 Comm: syz.0.42 Not tainted 6.10.0-syzkaller-12246-g786c8248dbd3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:488
kasan_report+0xd9/0x110 mm/kasan/report.c:601
bpf_net_ctx_get_all_used_flush_lists include/linux/filter.h:837 [inline]
xdp_do_check_flushed+0x41c/0x4e0 net/core/filter.c:4298
__napi_poll.constprop.0+0xd1/0x550 net/core/dev.c:6774
napi_poll net/core/dev.c:6840 [inline]
net_rx_action+0xa92/0x1010 net/core/dev.c:6962
handle_softirqs+0x216/0x8f0 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x95/0xb0 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:const_folio_flags.constprop.0+0x56/0x150 include/linux/page-flags.h:310
Code: 8b 6b 08 31 ff 83 e5 01 48 89 ee e8 84 cc ab ff 48 85 ed 0f 85 d4 00 00 00 e8 46 d1 ab ff 66 90 e8 3f d1 ab ff e8 3a d1 ab ff <48> 89 d8 5b 5d 41 5c c3 cc cc cc cc e8 29 d1 ab ff 48 89 dd 31 ff
RSP: 0018:ffffc900032bf6d0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffea00010118c0 RCX: ffffffff81deb54c
RDX: ffff8880274e8000 RSI: ffffffff81deb566 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000127
R13: ffff88802305c948 R14: ffffea00010118c0 R15: 0000000000000000
folio_test_swapbacked include/linux/page-flags.h:534 [inline]
folio_test_swapcache include/linux/page-flags.h:576 [inline]
free_swap_cache mm/swap_state.c:291 [inline]
free_pages_and_swap_cache+0x24e/0x510 mm/swap_state.c:325
__tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:366 [inline]
tlb_flush_mmu mm/mmu_gather.c:373 [inline]
tlb_finish_mmu+0x168/0x7b0 mm/mmu_gather.c:465
exit_mmap+0x3d1/0xb20 mm/mmap.c:3395
__mmput+0x12a/0x480 kernel/fork.c:1345
mmput+0x62/0x70 kernel/fork.c:1367
exit_mm kernel/exit.c:571 [inline]
do_exit+0x9bf/0x2bb0 kernel/exit.c:869
do_group_exit+0xd3/0x2a0 kernel/exit.c:1031
get_signal+0x25fd/0x2770 kernel/signal.c:2917
arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6f7c575b59
Code: Unable to access opcode bytes at 0x7f6f7c575b2f.
RSP: 002b:00007f6f7d27b0f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f6f7c705f68 RCX: 00007f6f7c575b59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6f7c705f68
RBP: 00007f6f7c705f60 R08: 00007f6f7d27b6c0 R09: 00007f6f7d27b6c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6f7c705f6c
R13: 000000000000000b R14: 00007ffd97f8d280 R15: 00007ffd97f8d368
</TASK>

The buggy address belongs to stack of task syz.0.42/5811
and is located at offset 24 in frame:
exit_mmap+0x0/0xb20 mm/mmap.c:3202

This frame has 2 objects:
[32, 96) 'vmi'
[128, 256) 'tlb'

The buggy address belongs to the virtual mapping at
[ffffc900032b8000, ffffc900032c1000) created by:
kernel_clone+0xfd/0x980 kernel/fork.c:2781

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802b3e0000 pfn:0x2b3e0
memcg:ffff8880206d0182
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: ffff88802b3e0000 0000000000000000 00000001ffffffff ffff8880206d0182
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 5653, tgid 5653 (syz-executor), ts 116595661744, free_ts 116458660012
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493
prep_new_page mm/page_alloc.c:1501 [inline]
get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3438
__alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4696
alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2263
vm_area_alloc_pages mm/vmalloc.c:3584 [inline]
__vmalloc_area_node mm/vmalloc.c:3660 [inline]
__vmalloc_node_range_noprof+0xa6a/0x1520 mm/vmalloc.c:3841
alloc_thread_stack_node kernel/fork.c:313 [inline]
dup_task_struct kernel/fork.c:1113 [inline]
copy_process+0x2f3b/0x8de0 kernel/fork.c:2204
kernel_clone+0xfd/0x980 kernel/fork.c:2781
__do_sys_clone+0xba/0x100 kernel/fork.c:2924
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5653 tgid 5653 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1094 [inline]
free_unref_page+0x64a/0xe40 mm/page_alloc.c:2608
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3988 [inline]
slab_alloc_node mm/slub.c:4037 [inline]
__kmalloc_cache_node_noprof+0x173/0x350 mm/slub.c:4197
kmalloc_node_noprof include/linux/slab.h:704 [inline]
__get_vm_area_node+0xe1/0x2d0 mm/vmalloc.c:3109
__vmalloc_node_range_noprof+0x276/0x1520 mm/vmalloc.c:3801
__vmalloc_node_noprof mm/vmalloc.c:3906 [inline]
vzalloc_noprof+0x6b/0x90 mm/vmalloc.c:3979
alloc_counters net/ipv4/netfilter/ip_tables.c:799 [inline]
copy_entries_to_user net/ipv4/netfilter/ip_tables.c:821 [inline]
get_entries net/ipv4/netfilter/ip_tables.c:1022 [inline]
do_ipt_get_ctl+0x6b8/0xaa0 net/ipv4/netfilter/ip_tables.c:1668
nf_getsockopt+0x79/0xe0 net/netfilter/nf_sockopt.c:116
ip_getsockopt+0x18e/0x1e0 net/ipv4/ip_sockglue.c:1777
tcp_getsockopt+0x9e/0x100 net/ipv4/tcp.c:4409
do_sock_getsockopt+0x2e5/0x760 net/socket.c:2386
__sys_getsockopt+0x1a1/0x270 net/socket.c:2415
__do_sys_getsockopt net/socket.c:2425 [inline]
__se_sys_getsockopt net/socket.c:2422 [inline]
__x64_sys_getsockopt+0xbd/0x160 net/socket.c:2422
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83

Memory state around the buggy address:
ffffc900032bf900: f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc900032bf980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900032bfa00: 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00
^
ffffc900032bfa80: 00 00 00 f2 f2 f2 f2 00 00 00 00 00 00 00 00 00
ffffc900032bfb00: 00 00 00 00 00 00 00 f3 f3 f3 f3 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: 8b 6b 08 mov 0x8(%rbx),%ebp
3: 31 ff xor %edi,%edi
5: 83 e5 01 and $0x1,%ebp
8: 48 89 ee mov %rbp,%rsi
b: e8 84 cc ab ff call 0xffabcc94
10: 48 85 ed test %rbp,%rbp
13: 0f 85 d4 00 00 00 jne 0xed
19: e8 46 d1 ab ff call 0xffabd164
1e: 66 90 xchg %ax,%ax
20: e8 3f d1 ab ff call 0xffabd164
25: e8 3a d1 ab ff call 0xffabd164
* 2a: 48 89 d8 mov %rbx,%rax <-- trapping instruction
2d: 5b pop %rbx
2e: 5d pop %rbp
2f: 41 5c pop %r12
31: c3 ret
32: cc int3
33: cc int3
34: cc int3
35: cc int3
36: e8 29 d1 ab ff call 0xffabd164
3b: 48 89 dd mov %rbx,%rbp
3e: 31 ff xor %edi,%edi

Tested on:

commit: 786c8248 Merge tag 'perf-tools-fixes-for-v6.11-2024-07..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1293bca1980000
kernel config: https://syzkaller.appspot.com/x/.config?x=47beaba1a1054668
dashboard link: https://syzkaller.appspot.com/bug?extid=44623300f057a28baf1e
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=11c0adad980000

Next message: Tejas Vipin: "[PATCH 0/2] Allow errors to be silenced in multi functions"
Previous message: Wim Van Sebroeck: "[GIT PULL REQUEST] watchdog - v6.11 release cycle."
In reply to: syzbot: "Re: [syzbot] [bpf?] [net?] general protection fault in __dev_flush"
Next in thread: syzbot: "Re: [syzbot] [bpf?] [net?] general protection fault in __dev_flush"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]