syzbot


KASAN: slab-use-after-free Read in sk_psock_verdict_data_ready

Status: moderation: reported on 2024/06/06 11:10
Subsystems: bpf net
[Documentation on labels]
Reported-by: syzbot+53ea6f0e9b559512d9c4@syzkaller.appspotmail.com
First crash: 12d, last: 12d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in sk_psock_verdict_data_ready net 2 374d 379d 0/27 auto-obsoleted due to no activity on 2023/09/14 09:29
upstream BUG: unable to handle kernel NULL pointer dereference in sk_psock_verdict_data_ready net bpf C unreliable 15 104d 224d 26/27 fixed on 2024/04/02 10:57
android-6-1 BUG: unable to handle kernel NULL pointer dereference in sk_psock_verdict_data_ready origin:upstream missing-backport C 164 22m 122d 0/2 upstream: reported C repro on 2024/02/13 08:31
linux-6.1 BUG: unable to handle kernel NULL pointer dereference in sk_psock_verdict_data_ready origin:upstream C done 1 121d 121d 3/3 fixed on 2024/03/18 12:46

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in sk_psock_verdict_data_ready+0x6d/0x390 net/core/skmsg.c:1220
Read of size 8 at addr ffff888076bac220 by task syz-executor.4/7751

CPU: 1 PID: 7751 Comm: syz-executor.4 Not tainted 6.10.0-rc1-syzkaller-g7d0b3953f6d8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 sk_psock_verdict_data_ready+0x6d/0x390 net/core/skmsg.c:1220
 unix_stream_sendmsg+0x7d5/0xf80 net/unix/af_unix.c:2299
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
 ___sys_sendmsg net/socket.c:2639 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcb3727cee9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcb37fc20c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fcb373b3fa0 RCX: 00007fcb3727cee9
RDX: 0000000000000000 RSI: 0000000020000500 RDI: 000000000000000a
RBP: 00007fcb372c947f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fcb373b3fa0 R15: 00007ffdc45ceac8
 </TASK>

Allocated by task 7751:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3940 [inline]
 slab_alloc_node mm/slub.c:4000 [inline]
 kmem_cache_alloc_lru_noprof+0x139/0x2b0 mm/slub.c:4019
 sock_alloc_inode+0x28/0xc0 net/socket.c:308
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x69/0x1e0 fs/inode.c:1007
 sock_alloc net/socket.c:634 [inline]
 __sock_create+0x123/0x920 net/socket.c:1535
 sock_create net/socket.c:1622 [inline]
 __sys_socketpair+0x2ca/0x720 net/socket.c:1769
 __do_sys_socketpair net/socket.c:1822 [inline]
 __se_sys_socketpair net/socket.c:1819 [inline]
 __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1819
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 7759:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2195 [inline]
 slab_free mm/slub.c:4436 [inline]
 kmem_cache_free+0x145/0x350 mm/slub.c:4511
 rcu_do_batch kernel/rcu/tree.c:2535 [inline]
 rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2809
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 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
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 __call_rcu_common kernel/rcu/tree.c:3072 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:3176
 __dentry_kill+0x20d/0x630 fs/dcache.c:603
 dput+0x19f/0x2b0 fs/dcache.c:845
 __fput+0x68c/0x8b0 fs/file_table.c:430
 __do_sys_close fs/open.c:1555 [inline]
 __se_sys_close fs/open.c:1540 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1540
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888076bac200
 which belongs to the cache sock_inode_cache of size 1408
The buggy address is located 32 bytes inside of
 freed 1408-byte region [ffff888076bac200, ffff888076bac780)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x76ba8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888029abeb01
ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 00fff00000000040 ffff888018ae0c80 ffffea0001764200 dead000000000003
raw: 0000000000000000 0000000000150015 00000001ffffefff ffff888029abeb01
head: 00fff00000000040 ffff888018ae0c80 ffffea0001764200 dead000000000003
head: 0000000000000000 0000000000150015 00000001ffffefff ffff888029abeb01
head: 00fff00000000003 ffffea0001daea01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_RECLAIMABLE), pid 5126, tgid 5126 (syz-executor.3), ts 61185062622, free_ts 14964246723
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468
 prep_new_page mm/page_alloc.c:1476 [inline]
 get_page_from_freelist+0x2e2d/0x2ee0 mm/page_alloc.c:3402
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4660
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2264
 allocate_slab+0x5a/0x2e0 mm/slub.c:2427
 new_slab mm/slub.c:2480 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3666
 __slab_alloc+0x58/0xa0 mm/slub.c:3756
 __slab_alloc_node mm/slub.c:3809 [inline]
 slab_alloc_node mm/slub.c:3988 [inline]
 kmem_cache_alloc_lru_noprof+0x1c5/0x2b0 mm/slub.c:4019
 sock_alloc_inode+0x28/0xc0 net/socket.c:308
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x69/0x1e0 fs/inode.c:1007
 sock_alloc net/socket.c:634 [inline]
 __sock_create+0x123/0x920 net/socket.c:1535
 sock_create net/socket.c:1622 [inline]
 __sys_socket_create net/socket.c:1659 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1706
 __do_sys_socket net/socket.c:1720 [inline]
 __se_sys_socket net/socket.c:1718 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1718
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1088 [inline]
 free_unref_page+0xd22/0xea0 mm/page_alloc.c:2565
 free_contig_range+0x9e/0x160 mm/page_alloc.c:6619
 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1038
 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1418
 do_one_initcall+0x248/0x880 init/main.c:1267
 do_initcall_level+0x157/0x210 init/main.c:1329
 do_initcalls+0x3f/0x80 init/main.c:1345
 kernel_init_freeable+0x435/0x5d0 init/main.c:1578
 kernel_init+0x1d/0x2b0 init/main.c:1467
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff888076bac100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888076bac180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888076bac200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888076bac280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888076bac300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/02 11:02 bpf 7d0b3953f6d8 3113787f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce KASAN: slab-use-after-free Read in sk_psock_verdict_data_ready
* Struck through repros no longer work on HEAD.