Message-ID: <67abaeaf.050a0220.110943.0041.GAE@google.com>
Date: Tue, 11 Feb 2025 12:10:23 -0800
From: syzbot <syzbot+402900951482ab0a6fcb@...kaller.appspotmail.com>
To: akpm@...ux-foundation.org, linux-kernel@...r.kernel.org, 
	linux-mm@...ck.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [mm?] KASAN: slab-use-after-free Read in folio_lock_anon_vma_read

Hello,

syzbot found the following issue on:

HEAD commit:    bb066fe812d6 Merge tag 'pci-v6.14-fixes-2' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=170aa1b0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c48f582603dcb16c
dashboard link: https://syzkaller.appspot.com/bug?extid=402900951482ab0a6fcb
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/988222f4ae63/disk-bb066fe8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/41a93a7bd0c9/vmlinux-bb066fe8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/99bd53f622e1/bzImage-bb066fe8.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+402900951482ab0a6fcb@...kaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in folio_lock_anon_vma_read+0xc4e/0xd40 mm/rmap.c:559
Read of size 8 at addr ffff888012dd7ee0 by task syz.0.7085/4643

CPU: 1 UID: 0 PID: 4643 Comm: syz.0.7085 Not tainted 6.14.0-rc1-syzkaller-00081-gbb066fe812d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 folio_lock_anon_vma_read+0xc4e/0xd40 mm/rmap.c:559
 rmap_walk_anon_lock mm/rmap.c:2579 [inline]
 rmap_walk_anon+0x485/0x710 mm/rmap.c:2627
 rmap_walk mm/rmap.c:2724 [inline]
 rmap_walk mm/rmap.c:2719 [inline]
 folio_referenced+0x2a8/0x5c0 mm/rmap.c:1015
 folio_check_references mm/vmscan.c:896 [inline]
 shrink_folio_list+0x1dee/0x40c0 mm/vmscan.c:1234
 evict_folios+0x774/0x1ab0 mm/vmscan.c:4660
 try_to_shrink_lruvec+0x5a2/0x9a0 mm/vmscan.c:4821
 lru_gen_shrink_lruvec mm/vmscan.c:4970 [inline]
 shrink_lruvec+0x313/0x2ba0 mm/vmscan.c:5715
 shrink_node_memcgs mm/vmscan.c:5951 [inline]
 shrink_node mm/vmscan.c:5992 [inline]
 shrink_node+0x105c/0x3f20 mm/vmscan.c:5970
 shrink_zones mm/vmscan.c:6237 [inline]
 do_try_to_free_pages+0x35f/0x1a30 mm/vmscan.c:6299
 try_to_free_mem_cgroup_pages+0x31a/0x7a0 mm/vmscan.c:6631
 try_charge_memcg+0x356/0xaf0 mm/memcontrol.c:2255
 try_charge mm/memcontrol-v1.h:19 [inline]
 charge_memcg+0x8a/0x310 mm/memcontrol.c:4487
 __mem_cgroup_charge+0x2b/0x1e0 mm/memcontrol.c:4504
 mem_cgroup_charge include/linux/memcontrol.h:644 [inline]
 shmem_alloc_and_add_folio+0x50a/0xc10 mm/shmem.c:1912
 shmem_get_folio_gfp+0x689/0x1530 mm/shmem.c:2522
 shmem_get_folio mm/shmem.c:2628 [inline]
 shmem_write_begin+0x161/0x300 mm/shmem.c:3278
 generic_perform_write+0x2ba/0x920 mm/filemap.c:4189
 shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3454
 __kernel_write_iter+0x318/0xa90 fs/read_write.c:612
 dump_emit_page fs/coredump.c:884 [inline]
 dump_user_range+0x389/0x8c0 fs/coredump.c:945
 elf_core_dump+0x2787/0x3880 fs/binfmt_elf.c:2129
 do_coredump+0x304f/0x45d0 fs/coredump.c:758
 get_signal+0x23f3/0x2610 kernel/signal.c:3021
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x4021000
Code: Unable to access opcode bytes at 0x4020fd6.
RSP: 002b:000000000000000d EFLAGS: 00010206
RAX: 0000000000000000 RBX: 00007fc4c91a5fa0 RCX: 00007fc4c8f8cde9
RDX: ffffffffffffffff RSI: 0000000000000005 RDI: 0000000000008001
RBP: 00007fc4c900e2a0 R08: 0000000000000006 R09: 0000000000000000
R10: ffffffffff600000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc4c91a5fa0 R15: 00007ffdab469bf8
 </TASK>

Allocated by task 4636:
 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:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 kmem_cache_alloc_noprof+0x1c8/0x3b0 mm/slub.c:4171
 anon_vma_alloc mm/rmap.c:94 [inline]
 anon_vma_fork+0xe6/0x620 mm/rmap.c:360
 dup_mmap kernel/fork.c:711 [inline]
 dup_mm kernel/fork.c:1700 [inline]
 copy_mm+0x1b7b/0x2730 kernel/fork.c:1752
 copy_process+0x3e6d/0x6f20 kernel/fork.c:2403
 kernel_clone+0xfd/0x960 kernel/fork.c:2815
 __do_sys_clone+0xba/0x100 kernel/fork.c:2958
 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

Freed by task 4644:
 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:2353 [inline]
 slab_free_after_rcu_debug+0x115/0x340 mm/slub.c:4659
 rcu_do_batch kernel/rcu/tree.c:2546 [inline]
 rcu_core+0x79d/0x14d0 kernel/rcu/tree.c:2802
 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
 __do_softirq kernel/softirq.c:595 [inline]
 invoke_softirq kernel/softirq.c:435 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:662
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
 sysvec_call_function_single+0xa4/0xc0 arch/x86/kernel/smp.c:266
 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709

Last potentially related work creation:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xb8/0xd0 mm/kasan/generic.c:548
 slab_free_hook mm/slub.c:2314 [inline]
 slab_free mm/slub.c:4609 [inline]
 kmem_cache_free+0x166/0x4d0 mm/slub.c:4711
 anon_vma_free mm/rmap.c:137 [inline]
 __put_anon_vma+0x114/0x3a0 mm/rmap.c:2568
 put_anon_vma include/linux/rmap.h:116 [inline]
 unlink_anon_vmas+0x58a/0x820 mm/rmap.c:444
 free_pgtables+0x33c/0x950 mm/memory.c:408
 exit_mmap+0x406/0xba0 mm/mmap.c:1295
 __mmput+0x12a/0x410 kernel/fork.c:1356
 mmput+0x62/0x70 kernel/fork.c:1378
 exec_mmap fs/exec.c:1011 [inline]
 begin_new_exec+0x152b/0x3800 fs/exec.c:1267
 load_elf_binary+0x85c/0x4ff0 fs/binfmt_elf.c:1002
 search_binary_handler fs/exec.c:1775 [inline]
 exec_binprm fs/exec.c:1807 [inline]
 bprm_execve fs/exec.c:1859 [inline]
 bprm_execve+0x8dd/0x16d0 fs/exec.c:1835
 do_execveat_common.isra.0+0x4a2/0x610 fs/exec.c:1966
 do_execve fs/exec.c:2040 [inline]
 __do_sys_execve fs/exec.c:2116 [inline]
 __se_sys_execve fs/exec.c:2111 [inline]
 __x64_sys_execve+0x8c/0xb0 fs/exec.c:2111
 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

The buggy address belongs to the object at ffff888012dd7ee0
 which belongs to the cache anon_vma of size 208
The buggy address is located 0 bytes inside of
 freed 208-byte region [ffff888012dd7ee0, ffff888012dd7fb0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888012dd7440 pfn:0x12dd7
memcg:ffff88802647a401
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88801c282140 ffff88801b0937c8 ffffea0000c9a210
raw: ffff888012dd7440 00000000000f000e 00000000f5000000 ffff88802647a401
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5503, tgid 5503 (dhcpcd), ts 67849640029, free_ts 55595562609
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739
 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2587 [inline]
 new_slab+0x23d/0x330 mm/slub.c:2640
 ___slab_alloc+0xbfa/0x1600 mm/slub.c:3826
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 kmem_cache_alloc_noprof+0xeb/0x3b0 mm/slub.c:4171
 anon_vma_alloc mm/rmap.c:94 [inline]
 anon_vma_fork+0xe6/0x620 mm/rmap.c:360
 dup_mmap kernel/fork.c:711 [inline]
 dup_mm kernel/fork.c:1700 [inline]
 copy_mm+0x1b7b/0x2730 kernel/fork.c:1752
 copy_process+0x3e6d/0x6f20 kernel/fork.c:2403
 kernel_clone+0xfd/0x960 kernel/fork.c:2815
 __do_sys_clone+0xba/0x100 kernel/fork.c:2958
 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 5502 tgid 5502 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660
 __put_partials+0x14c/0x170 mm/slub.c:3153
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 kmem_cache_alloc_node_noprof+0x1ca/0x3b0 mm/slub.c:4216
 __alloc_skb+0x2b3/0x380 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1331 [inline]
 netlink_alloc_large_skb+0x69/0x130 net/netlink/af_netlink.c:1196
 netlink_sendmsg+0x689/0xd70 net/netlink/af_netlink.c:1867
 sock_sendmsg_nosec net/socket.c:713 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2568
 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2622
 __sys_sendmsg+0x16e/0x220 net/socket.c:2654
 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

Memory state around the buggy address:
 ffff888012dd7d80: 00 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb
 ffff888012dd7e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888012dd7e80: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb
                                                       ^
 ffff888012dd7f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888012dd7f80: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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