syzbot

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BUG: KASAN: slab-use-after-free in sk_psock_verdict_data_ready+0x412/0x440 net/core/skmsg.c:1247
Read of size 8 at addr ffff888077dd8020 by task syz.1.7419/30559

CPU: 0 UID: 0 PID: 30559 Comm: syz.1.7419 Not tainted 6.16.0-rc3-syzkaller-00233-g35e261cd95dd #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xcd/0x680 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 sk_psock_verdict_data_ready+0x412/0x440 net/core/skmsg.c:1247
 unix_stream_sendmsg+0x629/0x11d0 net/unix/af_unix.c:2423
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2566
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
 __sys_sendmsg+0x16d/0x220 net/socket.c:2652
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe5cfd8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe5d0b7e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe5cffb6080 RCX: 00007fe5cfd8e929
RDX: 0000000000000000 RSI: 00002000000029c0 RDI: 0000000000000007
RBP: 00007fe5cfe10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe5cffb6080 R15: 00007ffeb89b0bb8
 </TASK>

Allocated by task 30559:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_lru_noprof+0x1d0/0x3b0 mm/slub.c:4216
 sock_alloc_inode+0x25/0x1c0 net/socket.c:309
 alloc_inode+0x64/0x240 fs/inode.c:346
 new_inode_pseudo include/linux/fs.h:3364 [inline]
 sock_alloc+0x40/0x280 net/socket.c:622
 __sock_create+0xc1/0x8d0 net/socket.c:1505
 sock_create net/socket.c:1599 [inline]
 __sys_socketpair+0x1d8/0x5a0 net/socket.c:1746
 __do_sys_socketpair net/socket.c:1799 [inline]
 __se_sys_socketpair net/socket.c:1796 [inline]
 __x64_sys_socketpair+0x96/0x100 net/socket.c:1796
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 30565:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4745
 i_callback+0x46/0x70 fs/inode.c:325
 rcu_do_batch kernel/rcu/tree.c:2576 [inline]
 rcu_core+0x79c/0x14e0 kernel/rcu/tree.c:2832
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Last potentially related work creation:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548
 __call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3094
 destroy_inode+0x12c/0x1b0 fs/inode.c:401
 evict+0x5b4/0x920 fs/inode.c:834
 iput_final fs/inode.c:1898 [inline]
 iput fs/inode.c:1924 [inline]
 iput+0x521/0x880 fs/inode.c:1910
 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:466
 __dentry_kill+0x1d0/0x600 fs/dcache.c:669
 dput.part.0+0x4b1/0x9b0 fs/dcache.c:911
 dput+0x1f/0x30 fs/dcache.c:901
 __fput+0x51c/0xb70 fs/file_table.c:473
 task_work_run+0x150/0x240 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888077dd8000
 which belongs to the cache sock_inode_cache of size 1408
The buggy address is located 32 bytes inside of
 freed 1408-byte region [ffff888077dd8000, ffff888077dd8580)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77dd8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888029e7c801
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888140aed640 ffffea0000f6ea00 dead000000000002
raw: 0000000000000000 0000000000150015 00000000f5000000 ffff888029e7c801
head: 00fff00000000040 ffff888140aed640 ffffea0000f6ea00 dead000000000002
head: 0000000000000000 0000000000150015 00000000f5000000 ffff888029e7c801
head: 00fff00000000003 ffffea0001df7601 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
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_RECLAIMABLE|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5576, tgid 5576 (sshd), ts 82828636047, free_ts 46606480195
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab mm/slub.c:2619 [inline]
 new_slab+0x23b/0x330 mm/slub.c:2673
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 kmem_cache_alloc_lru_noprof+0xf4/0x3b0 mm/slub.c:4216
 sock_alloc_inode+0x25/0x1c0 net/socket.c:309
 alloc_inode+0x64/0x240 fs/inode.c:346
 new_inode_pseudo include/linux/fs.h:3364 [inline]
 sock_alloc+0x40/0x280 net/socket.c:622
 __sock_create+0xc1/0x8d0 net/socket.c:1505
 sock_create net/socket.c:1599 [inline]
 __sys_socket_create net/socket.c:1636 [inline]
 __sys_socket+0x14d/0x260 net/socket.c:1683
 __do_sys_socket net/socket.c:1697 [inline]
 __se_sys_socket net/socket.c:1695 [inline]
 __x64_sys_socket+0x72/0xb0 net/socket.c:1695
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 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:1248 [inline]
 __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706
 __free_pages mm/page_alloc.c:5071 [inline]
 free_contig_range+0x183/0x4b0 mm/page_alloc.c:6927
 destroy_args+0x7f6/0xa60 mm/debug_vm_pgtable.c:1009
 debug_vm_pgtable+0x13b8/0x2d00 mm/debug_vm_pgtable.c:1389
 do_one_initcall+0x123/0x6e0 init/main.c:1274
 do_initcall_level init/main.c:1336 [inline]
 do_initcalls init/main.c:1352 [inline]
 do_basic_setup init/main.c:1371 [inline]
 kernel_init_freeable+0x5c2/0x900 init/main.c:1584
 kernel_init+0x1c/0x2b0 init/main.c:1474
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff888077dd7f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888077dd7f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888077dd8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888077dd8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888077dd8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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