================================================================== BUG: KASAN: slab-use-after-free in v9fs_stat2inode_dotl+0x41/0xb00 fs/9p/vfs_inode_dotl.c:569 Read of size 8 at addr ffff8880a09b8000 by task syz-executor.4/7962 CPU: 1 PID: 7962 Comm: syz-executor.4 Not tainted 6.8.0-rc4-next-20240214-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __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 v9fs_stat2inode_dotl+0x41/0xb00 fs/9p/vfs_inode_dotl.c:569 v9fs_fid_iget_dotl+0x186/0x210 fs/9p/vfs_inode_dotl.c:85 v9fs_get_inode_from_fid fs/9p/v9fs.h:230 [inline] v9fs_mount+0x7f9/0xa90 fs/9p/vfs_super.c:142 legacy_get_tree+0xee/0x190 fs/fs_context.c:662 vfs_get_tree+0x90/0x2a0 fs/super.c:1784 do_new_mount+0x2be/0xb40 fs/namespace.c:3352 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fc04b47dda9 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:00007fc04c1780c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc04b5abf80 RCX: 00007fc04b47dda9 RDX: 0000000020000000 RSI: 00000000200002c0 RDI: 0000000000000000 RBP: 00007fc04b4ca47a R08: 0000000020000140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc04b5abf80 R15: 00007ffc7e7a1008 Allocated by task 7962: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x1d9/0x360 mm/slub.c:4013 kmalloc include/linux/slab.h:590 [inline] p9_client_getattr_dotl+0x57/0x1a0 net/9p/client.c:1726 v9fs_fid_iget_dotl+0xca/0x210 fs/9p/vfs_inode_dotl.c:73 v9fs_get_inode_from_fid fs/9p/v9fs.h:230 [inline] v9fs_mount+0x7f9/0xa90 fs/9p/vfs_super.c:142 legacy_get_tree+0xee/0x190 fs/fs_context.c:662 vfs_get_tree+0x90/0x2a0 fs/super.c:1784 do_new_mount+0x2be/0xb40 fs/namespace.c:3352 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Freed by task 7962: 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:586 poison_slab_object+0xa6/0xe0 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:2122 [inline] slab_free mm/slub.c:4296 [inline] kfree+0x14a/0x380 mm/slub.c:4406 v9fs_fid_iget_dotl+0x162/0x210 fs/9p/vfs_inode_dotl.c:81 v9fs_get_inode_from_fid fs/9p/v9fs.h:230 [inline] v9fs_mount+0x7f9/0xa90 fs/9p/vfs_super.c:142 legacy_get_tree+0xee/0x190 fs/fs_context.c:662 vfs_get_tree+0x90/0x2a0 fs/super.c:1784 do_new_mount+0x2be/0xb40 fs/namespace.c:3352 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 The buggy address belongs to the object at ffff8880a09b8000 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 0 bytes inside of freed 192-byte region [ffff8880a09b8000, ffff8880a09b80c0) The buggy address belongs to the physical page: page:ffffea0002826e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa09b8 flags: 0xfff80000000800(slab|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffffff() raw: 00fff80000000800 ffff888014c41a00 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000001ffffffff 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 4816, tgid 4814 (syz-executor.2), ts 2186898489296, free_ts 2186828999380 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311 __alloc_pages+0x256/0x6a0 mm/page_alloc.c:4567 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2191 allocate_slab mm/slub.c:2354 [inline] new_slab+0x84/0x2f0 mm/slub.c:2407 ___slab_alloc+0xc73/0x1260 mm/slub.c:3541 __slab_alloc mm/slub.c:3626 [inline] __slab_alloc_node mm/slub.c:3679 [inline] slab_alloc_node mm/slub.c:3851 [inline] __do_kmalloc_node mm/slub.c:3981 [inline] __kmalloc+0x2e3/0x4a0 mm/slub.c:3995 kmalloc include/linux/slab.h:594 [inline] kzalloc include/linux/slab.h:711 [inline] ops_init+0x8b/0x610 net/core/net_namespace.c:126 setup_net+0x515/0xca0 net/core/net_namespace.c:340 copy_net_ns+0x4e4/0x7b0 net/core/net_namespace.c:505 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 copy_namespaces+0x41a/0x490 kernel/nsproxy.c:179 copy_process+0x195e/0x3df0 kernel/fork.c:2511 kernel_clone+0x21e/0x8d0 kernel/fork.c:2915 __do_sys_clone kernel/fork.c:3058 [inline] __se_sys_clone kernel/fork.c:3042 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:3042 do_syscall_64+0xfb/0x240 page last free pid 4824 tgid 4820 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x968/0xa90 mm/page_alloc.c:2346 free_unref_page_list+0x5a3/0x850 mm/page_alloc.c:2532 release_pages+0x2744/0x2a80 mm/swap.c:1042 tlb_batch_pages_flush mm/mmu_gather.c:98 [inline] tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] tlb_flush_mmu+0x34d/0x4e0 mm/mmu_gather.c:300 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:392 exit_mmap+0x4b6/0xd40 mm/mmap.c:3272 __mmput+0x115/0x3c0 kernel/fork.c:1344 exit_mm+0x220/0x310 kernel/exit.c:569 do_exit+0x99e/0x27e0 kernel/exit.c:865 do_group_exit+0x207/0x2c0 kernel/exit.c:1027 get_signal+0x176e/0x1850 kernel/signal.c:2907 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:212 do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Memory state around the buggy address: ffff8880a09b7f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a09b7f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a09b8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a09b8080: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880a09b8100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================