syzbot


KASAN: slab-out-of-bounds Read in generic_perform_write

Status: upstream: reported on 2023/09/17 14:11
Reported-by: syzbot+00d2a588c9e933bd551c@syzkaller.appspotmail.com
First crash: 159d, last: 18d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-out-of-bounds Read in generic_perform_write hfs mm C inconclusive 10195 1d13h 153d 0/26 upstream: reported C repro on 2023/09/24 07:49
linux-6.1 KASAN: use-after-free Read in generic_perform_write origin:upstream C unreliable 10 4d18h 165d 0/3 upstream: reported C repro on 2023/09/12 02:51
linux-4.14 KASAN: use-after-free Read in generic_perform_write (2) hfsplus jfs C error 20 393d 811d 0/1 upstream: reported C repro on 2021/12/05 01:05
linux-4.19 KASAN: use-after-free Read in generic_perform_write hfsplus jfs C error 68 356d 1248d 0/1 upstream: reported C repro on 2020/09/24 08:55
linux-4.14 KASAN: use-after-free Read in generic_perform_write 11 1016d 1246d 0/1 auto-closed as invalid on 2021/09/11 00:48
upstream KASAN: use-after-free Read in generic_perform_write fs mm C error 73 983d 2045d 0/26 auto-obsoleted due to no activity on 2023/04/14 08:17

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in copy_page_from_iter_atomic+0x8e3/0x1230 lib/iov_iter.c:978
Read of size 2048 at addr ffff88807622d400 by task kworker/u4:12/3699

CPU: 0 PID: 3699 Comm: kworker/u4:12 Not tainted 5.15.134-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: loop0 loop_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 kasan_check_range+0x27e/0x290 mm/kasan/generic.c:189
 memcpy+0x25/0x60 mm/kasan/shadow.c:65
 copy_page_from_iter_atomic+0x8e3/0x1230 lib/iov_iter.c:978
 generic_perform_write+0x33a/0x5b0 mm/filemap.c:3784
 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3903
 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3935
 do_iter_readv_writev+0x594/0x7a0
 do_iter_write+0x1ea/0x760 fs/read_write.c:855
 lo_write_bvec+0x297/0x740 drivers/block/loop.c:316
 lo_write_simple drivers/block/loop.c:338 [inline]
 do_req_filebacked drivers/block/loop.c:656 [inline]
 loop_handle_cmd drivers/block/loop.c:2234 [inline]
 loop_process_work+0x2309/0x2af0 drivers/block/loop.c:2274
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Allocated by task 4823:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc+0x168/0x300 mm/slub.c:4407
 kmalloc include/linux/slab.h:596 [inline]
 hfsplus_read_wrapper+0x4e3/0x13b0 fs/hfsplus/wrapper.c:180
 hfsplus_fill_super+0x38a/0x1c90 fs/hfsplus/super.c:413
 mount_bdev+0x2c9/0x3f0 fs/super.c:1387
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1517
 do_new_mount+0x28b/0xae0 fs/namespace.c:2994
 do_mount fs/namespace.c:3337 [inline]
 __do_sys_mount fs/namespace.c:3545 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff88807622d400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes inside of
 512-byte region [ffff88807622d400, ffff88807622d600)
The buggy address belongs to the page:
page:ffffea0001d88b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7622c
head:ffffea0001d88b00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888011c41c80
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 20, ts 117041419749, free_ts 103293123463
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 __kmalloc_node_track_caller+0x1f6/0x390 mm/slub.c:4958
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x12c/0x590 net/core/skbuff.c:427
 __napi_alloc_skb+0x15c/0x2d0 net/core/skbuff.c:568
 napi_alloc_skb include/linux/skbuff.h:3046 [inline]
 page_to_skb+0x294/0xd20 drivers/net/virtio_net.c:454
 receive_mergeable drivers/net/virtio_net.c:1070 [inline]
 receive_buf+0x1218/0x64c0 drivers/net/virtio_net.c:1180
 virtnet_receive drivers/net/virtio_net.c:1472 [inline]
 virtnet_poll+0x629/0x1270 drivers/net/virtio_net.c:1585
 __napi_poll+0xc7/0x440 net/core/dev.c:7012
 napi_poll net/core/dev.c:7079 [inline]
 net_rx_action+0x617/0xda0 net/core/dev.c:7166
 __do_softirq+0x3b3/0x93a kernel/softirq.c:558
 run_ksoftirqd+0xc1/0x120 kernel/softirq.c:921
 smpboot_thread_fn+0x51b/0x9d0 kernel/smpboot.c:164
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 put_page include/linux/mm.h:1247 [inline]
 __skb_frag_unref include/linux/skbuff.h:3219 [inline]
 skb_release_data+0x411/0x8a0 net/core/skbuff.c:672
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb+0x4c/0x60 net/core/skbuff.c:756
 sk_eat_skb include/net/sock.h:2704 [inline]
 tcp_recvmsg_locked+0x1629/0x29b0 net/ipv4/tcp.c:2512
 tcp_recvmsg+0x24e/0x7f0 net/ipv4/tcp.c:2558
 inet_recvmsg+0x157/0x280 net/ipv4/af_inet.c:856
 sock_recvmsg_nosec net/socket.c:947 [inline]
 sock_recvmsg net/socket.c:965 [inline]
 sock_read_iter+0x353/0x480 net/socket.c:1038
 call_read_iter include/linux/fs.h:2097 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0xa9f/0xe10 fs/read_write.c:485
 ksys_read+0x1a2/0x2c0 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff88807622d500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88807622d580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807622d600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff88807622d680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807622d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/10/09 19:44 linux-5.15.y 1edcec18cfb7 3c53c7d9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in generic_perform_write
2024/02/05 15:05 linux-5.15.y 6139f2a02fe0 e23e8c20 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in generic_perform_write
2024/02/04 16:07 linux-5.15.y 6139f2a02fe0 a67b2c42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in generic_perform_write
2024/02/02 02:21 linux-5.15.y 6139f2a02fe0 d61103fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in generic_perform_write
2023/09/17 14:10 linux-5.15.y aff03380bda4 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in generic_perform_write
2023/12/22 21:46 linux-5.15.y 1d146b1875fc fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in generic_perform_write
2023/12/29 11:46 linux-5.15.y d93fa2c78854 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in generic_perform_write
* Struck through repros no longer work on HEAD.