syzbot

 sign-in | mailing list | source | docs
🐞 Open [546] 🐞 Fixed [32] 🐞 Invalid [297] ⬇ Missing Backports [45] 📈 Kernel Health 📈 Bug Lifetimes 📈 Fuzzing 📈 Crashes 💬 Send us feedback

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

Status: upstream: reported C repro on 2023/09/17 14:11
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+00d2a588c9e933bd551c@syzkaller.appspotmail.com
First crash: 222d, last: 3d04h
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2024/03/12 upstream (ToT) 855684c7d938 C [report] KASAN: slab-out-of-bounds Read in generic_perform_write
▶ ▼ 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 10215 5h59m 215d 0/26 upstream: reported C repro on 2023/09/24 07:49
linux-6.1 KASAN: use-after-free Read in generic_perform_write C unreliable 16 11d 228d 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 456d 874d 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 419d 1310d 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 1079d 1308d 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 1046d 2108d 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+0x834/0xffc lib/iov_iter.c:978
Read of size 2048 at addr ffff0000d17ad400 by task kworker/u4:1/136

CPU: 1 PID: 136 Comm: kworker/u4:1 Not tainted 5.15.152-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: loop0 loop_rootcg_workfn
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x174/0x1e4 mm/kasan/report.c:451
 kasan_check_range+0x274/0x2b4 mm/kasan/generic.c:189
 memcpy+0x90/0xe8 mm/kasan/shadow.c:65
 copy_page_from_iter_atomic+0x834/0xffc lib/iov_iter.c:978
 generic_perform_write+0x2d0/0x520 mm/filemap.c:3793
 __generic_file_write_iter+0x230/0x454 mm/filemap.c:3912
 generic_file_write_iter+0xb4/0x1b8 mm/filemap.c:3944
 do_iter_readv_writev+0x420/0x5f8
 do_iter_write+0x1b8/0x664 fs/read_write.c:855
 vfs_iter_write+0x88/0xac fs/read_write.c:896
 lo_write_bvec+0x394/0xb4c 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+0x1f24/0x2798 drivers/block/loop.c:2274
 loop_rootcg_workfn+0x28/0x38 drivers/block/loop.c:2305
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 worker_thread+0x910/0x1034 kernel/workqueue.c:2457
 kthread+0x37c/0x45c kernel/kthread.c:319
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Allocated by task 3961:
 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+0xbc/0xfc mm/kasan/common.c:513
 __kasan_kmalloc+0x10/0x1c mm/kasan/common.c:522
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc+0x29c/0x4c8 mm/slub.c:4407
 kmalloc include/linux/slab.h:596 [inline]
 hfsplus_read_wrapper+0x3b8/0xfc8 fs/hfsplus/wrapper.c:180
 hfsplus_fill_super+0x2f0/0x167c fs/hfsplus/super.c:413
 mount_bdev+0x274/0x370 fs/super.c:1387
 hfsplus_mount+0x44/0x58 fs/hfsplus/super.c:641
 legacy_get_tree+0xd4/0x16c fs/fs_context.c:611
 vfs_get_tree+0x90/0x274 fs/super.c:1517
 do_new_mount+0x278/0x8fc fs/namespace.c:3005
 path_mount+0x594/0x101c fs/namespace.c:3335
 do_mount fs/namespace.c:3348 [inline]
 __do_sys_mount fs/namespace.c:3556 [inline]
 __se_sys_mount fs/namespace.c:3533 [inline]
 __arm64_sys_mount+0x510/0x5e0 fs/namespace.c:3533
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the object at ffff0000d17ad400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes inside of
 512-byte region [ffff0000d17ad400, ffff0000d17ad600)
The buggy address belongs to the page:
page:000000000fc12783 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1117ac
head:000000000fc12783 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 dead000000000100 dead000000000122 ffff0000c0002600
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d17ad500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000d17ad580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000d17ad600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff0000d17ad680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000d17ad700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/23 00:42 linux-5.15.y b95c01af2113 4b6cdce6 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in generic_perform_write
2024/03/12 10:22 linux-5.15.y 574362648507 6ee49f2e .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: slab-out-of-bounds Read in generic_perform_write
2024/04/04 18:35 linux-5.15.y 9465fef4ae35 0ee3535e .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
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
2024/03/15 20:20 linux-5.15.y b95c01af2113 d615901c .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
2024/02/25 05:06 linux-5.15.y 458ce51d0356 8d446f15 .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
2024/02/05 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
2024/04/24 03:19 linux-5.15.y c52b9710c83d 21339d7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in generic_perform_write
2024/03/20 15:24 linux-5.15.y b95c01af2113 5b7d42ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in generic_perform_write
2023/12/22 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.