9pnet: Found fid 4 not clunked ================================================================== BUG: KASAN: slab-use-after-free in p9_fid_destroy+0xb5/0xd0 net/9p/client.c:885 Read of size 8 at addr ffff888021811000 by task syz-executor.0/12318 CPU: 0 PID: 12318 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-12333-g54f71b0369c9 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 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 p9_fid_destroy+0xb5/0xd0 net/9p/client.c:885 p9_client_destroy+0x14c/0x480 net/9p/client.c:1071 v9fs_session_close+0x49/0x2d0 fs/9p/v9fs.c:506 v9fs_kill_super+0x4d/0xa0 fs/9p/vfs_super.c:196 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super+0xde/0x100 fs/super.c:506 cleanup_mnt+0x222/0x450 fs/namespace.c:1267 task_work_run+0x14e/0x250 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x278/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7261579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000ffce5f48 EFLAGS: 00000292 ORIG_RAX: 0000000000000034 RAX: 0000000000000000 RBX: 00000000ffce5ff0 RCX: 0000000000000009 RDX: 00000000f73b7ff4 RSI: 00000000f7308361 RDI: 00000000ffce7094 RBP: 00000000ffce5ff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 13745: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] p9_fid_create+0x45/0x470 net/9p/client.c:854 p9_client_walk+0xc7/0x550 net/9p/client.c:1155 clone_fid fs/9p/fid.h:23 [inline] v9fs_create+0x10a/0x6c0 fs/9p/vfs_inode.c:553 v9fs_vfs_atomic_open+0x29d/0x950 fs/9p/vfs_inode.c:762 atomic_open fs/namei.c:3368 [inline] lookup_open.isra.0+0xc98/0x13c0 fs/namei.c:3476 open_last_lookups fs/namei.c:3574 [inline] path_openat+0x92f/0x29f0 fs/namei.c:3804 do_filp_open+0x1dc/0x430 fs/namei.c:3834 do_sys_openat2+0x17a/0x1e0 fs/open.c:1405 do_sys_open fs/open.c:1420 [inline] __do_compat_sys_openat fs/open.c:1480 [inline] __se_compat_sys_openat fs/open.c:1478 [inline] __ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1478 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 82: 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:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 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] kfree+0x12a/0x3b0 mm/slub.c:4557 p9_client_clunk+0x12a/0x170 net/9p/client.c:1457 p9_fid_put include/net/9p/client.h:280 [inline] v9fs_free_request+0xdc/0x110 fs/9p/vfs_addr.c:138 netfs_free_request+0x22c/0x690 fs/netfs/objects.c:133 netfs_put_request+0x19b/0x1f0 fs/netfs/objects.c:165 netfs_write_collection_worker+0x19d0/0x59e0 fs/netfs/write_collect.c:701 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff888021811000 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of freed 96-byte region [ffff888021811000, ffff888021811060) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21811 ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffefff(slab) raw: 00fff00000000000 ffff888015442280 ffffea00009c2680 dead000000000003 raw: 0000000000000000 0000000000200020 00000001ffffefff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 4694, tgid 4694 (udevd), ts 24416842006, free_ts 24327940465 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1468 prep_new_page mm/page_alloc.c:1476 [inline] get_page_from_freelist+0x136a/0x2df0 mm/page_alloc.c:3402 __alloc_pages_noprof+0x22b/0x2460 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+0x56/0x110 mm/slub.c:2264 allocate_slab mm/slub.c:2427 [inline] new_slab+0x84/0x260 mm/slub.c:2480 ___slab_alloc+0xdac/0x1870 mm/slub.c:3666 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3756 __slab_alloc_node mm/slub.c:3809 [inline] slab_alloc_node mm/slub.c:3988 [inline] __do_kmalloc_node mm/slub.c:4120 [inline] __kmalloc_noprof+0x37f/0x420 mm/slub.c:4134 kmalloc_noprof include/linux/slab.h:664 [inline] kmalloc_array_noprof include/linux/slab.h:699 [inline] ext4_find_extent+0x95c/0xce0 fs/ext4/extents.c:914 ext4_ext_map_blocks+0x27d/0x5cd0 fs/ext4/extents.c:4144 ext4_map_blocks+0x848/0x17d0 fs/ext4/inode.c:551 ext4_mpage_readpages+0xf14/0x1af0 fs/ext4/readpage.c:290 ext4_readahead+0x102/0x140 fs/ext4/inode.c:3140 read_pages+0x1a8/0xd80 mm/readahead.c:160 page_cache_ra_unbounded+0x2d8/0x5a0 mm/readahead.c:273 do_page_cache_ra mm/readahead.c:303 [inline] page_cache_ra_order+0x6c6/0xa80 mm/readahead.c:547 page last free pid 816 tgid 816 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1088 [inline] free_unref_page+0x64a/0xe40 mm/page_alloc.c:2565 vfree+0x181/0x7a0 mm/vmalloc.c:3346 delayed_vfree_work+0x56/0x70 mm/vmalloc.c:3267 process_one_work+0x958/0x1ad0 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: ffff888021810f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888021810f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888021811000: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888021811080: 00 00 00 00 00 00 00 00 00 01 fc fc fc fc fc fc ffff888021811100: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi