syzbot


KASAN: use-after-free Read in skb_release_head_state

Status: upstream: reported on 2024/04/25 21:25
Reported-by: syzbot+08daa8cf5175eaf6ed58@syzkaller.appspotmail.com
First crash: 60d, last: 8d16h
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in skb_release_head_state bluetooth 1 1262d 1258d 0/27 auto-closed as invalid on 2021/05/09 12:11
upstream KASAN: slab-use-after-free Read in skb_release_head_state bluetooth syz 104 2h21m 63d 0/27 upstream: reported syz repro on 2024/04/22 06:47

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in skb_dst_drop include/net/dst.h:267 [inline]
BUG: KASAN: use-after-free in skb_release_head_state+0x35/0x230 net/core/skbuff.c:840
Read of size 8 at addr ffff88805e1d37d8 by task syz-executor.4/3565

CPU: 1 PID: 3565 Comm: syz-executor.4 Not tainted 6.1.87-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:395
 kasan_report+0x136/0x160 mm/kasan/report.c:495
 skb_dst_drop include/net/dst.h:267 [inline]
 skb_release_head_state+0x35/0x230 net/core/skbuff.c:840
 skb_release_all net/core/skbuff.c:854 [inline]
 __kfree_skb net/core/skbuff.c:870 [inline]
 kfree_skb_reason+0x13d/0x390 net/core/skbuff.c:893
 kfree_skb include/linux/skbuff.h:1220 [inline]
 __hci_req_sync+0x626/0x940 net/bluetooth/hci_request.c:184
 hci_req_sync+0xa5/0xc0 net/bluetooth/hci_request.c:206
 hci_dev_cmd+0x2fc/0xa30 net/bluetooth/hci_core.c:790
 sock_do_ioctl+0x152/0x450 net/socket.c:1204
 sock_ioctl+0x47f/0x770 net/socket.c:1321
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb6f707dc0b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007ffc4ba82080 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fb6f707dc0b
RDX: 00007ffc4ba820f8 RSI: 00000000400448dd RDI: 0000000000000003
RBP: 00005555560e7430 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000000000004 R14: 00007fb6f71ac9d8 R15: 000000000000000c
 </TASK>

Allocated by task 3569:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x10c/0x2d0 mm/slub.c:3422
 skb_clone+0x1e5/0x360 net/core/skbuff.c:1660
 hci_send_cmd_sync net/bluetooth/hci_core.c:4179 [inline]
 hci_cmd_work+0x296/0x660 net/bluetooth/hci_core.c:4199
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Freed by task 3571:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0x292/0x510 mm/slub.c:3683
 kfree_skb include/linux/skbuff.h:1220 [inline]
 hci_req_sync_complete+0xee/0x280 net/bluetooth/hci_request.c:109
 hci_event_packet+0xc49/0x1510 net/bluetooth/hci_event.c:7601
 hci_rx_work+0x3cd/0xce0 net/bluetooth/hci_core.c:4130
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

The buggy address belongs to the object at ffff88805e1d3780
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 88 bytes inside of
 240-byte region [ffff88805e1d3780, ffff88805e1d3870)

The buggy address belongs to the physical page:
page:ffffea00017874c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e1d3
flags: 0xfff80000000200(slab|node=0|zone=1|lastcpupid=0xfff)
raw: 00fff80000000200 0000000000000000 dead000000000122 ffff888013e54500
raw: 0000000000000000 00000000800c000c 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 3570, tgid 3564 (syz-executor.2), ts 53010471066, free_ts 11270153854
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513
 prep_new_page mm/page_alloc.c:2520 [inline]
 get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5547
 alloc_slab_page+0x6a/0x150 mm/slub.c:1794
 allocate_slab mm/slub.c:1939 [inline]
 new_slab+0x84/0x2d0 mm/slub.c:1992
 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 kmem_cache_alloc_node+0x1cf/0x310 mm/slub.c:3443
 __alloc_skb+0xde/0x670 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1271 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:469 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:396 [inline]
 vhci_write+0xbc/0x440 drivers/bluetooth/hci_vhci.c:516
 do_iter_write+0x6e6/0xc50 fs/read_write.c:861
 vfs_writev fs/read_write.c:934 [inline]
 do_writev+0x27b/0x460 fs/read_write.c:977
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1440 [inline]
 free_pcp_prepare mm/page_alloc.c:1490 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3358
 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3453
 free_contig_range+0x9a/0x150 mm/page_alloc.c:9507
 destroy_args+0xfe/0x997 mm/debug_vm_pgtable.c:1031
 debug_vm_pgtable+0x416/0x46b mm/debug_vm_pgtable.c:1354
 do_one_initcall+0x265/0x8f0 init/main.c:1297
 do_initcall_level+0x157/0x207 init/main.c:1370
 do_initcalls+0x49/0x86 init/main.c:1386
 kernel_init_freeable+0x45c/0x60f init/main.c:1625
 kernel_init+0x19/0x290 init/main.c:1513
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Memory state around the buggy address:
 ffff88805e1d3680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805e1d3700: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>ffff88805e1d3780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff88805e1d3800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff88805e1d3880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/25 21:25 linux-6.1.y 6741e066ec76 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf KASAN: use-after-free Read in skb_release_head_state
2024/06/16 06:40 linux-6.1.y ae9f2a70d69e f429ab00 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: use-after-free Read in skb_release_head_state
2024/06/10 21:40 linux-6.1.y 88690811da69 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 KASAN: use-after-free Read in skb_release_head_state
* Struck through repros no longer work on HEAD.