From: syzbot ci <syzbot+ci64ff753c2913b080@syzkaller.appspotmail.com>
To: akpm@linux-foundation.org, apopple@nvidia.com, arnd@arndb.de,
baohua@kernel.org, baolin.wang@linux.alibaba.com,
byungchul@sk.com, chengming.zhou@linux.dev, david@kernel.org,
dev.jain@arm.com, gourry@gourry.net, gregkh@linuxfoundation.org,
harry@kernel.org, jack@suse.cz, jannh@google.com,
joshua.hahnjy@gmail.com, kees@kernel.org, lance.yang@linux.dev,
liam@infradead.org, linmiaohe@huawei.com,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
ljs@kernel.org, matthew.brost@intel.com, mhocko@suse.com,
nao.horiguchi@gmail.com, npache@redhat.com, peterx@redhat.com,
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rppt@kernel.org, ryan.roberts@arm.com, surenb@google.com,
usama.arif@linux.dev, vbabka@kernel.org, willy@infradead.org,
xu.xin16@zte.com.cn, ying.huang@linux.alibaba.com,
ziy@nvidia.com
Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com
Subject: [syzbot ci] Re: mm/rmap: index MAP_PRIVATE file-backed folios by virt pgoff
Date: Fri, 17 Jul 2026 23:47:18 -0700 [thread overview]
Message-ID: <6a5b2176.5028b7d0.1f0bb.00e1.GAE@google.com> (raw)
In-Reply-To: <20260717-b4-scalable-cow-virt-pgoff-v1-0-cf24910ef094@kernel.org>
syzbot ci has tested the following series
[v1] mm/rmap: index MAP_PRIVATE file-backed folios by virt pgoff
https://lore.kernel.org/all/20260717-b4-scalable-cow-virt-pgoff-v1-0-cf24910ef094@kernel.org
* [PATCH 01/15] mm/vma: introduce VMA virtual page offset field and add helpers
* [PATCH 02/15] mm: introduce linear_virt_page_index()
* [PATCH 03/15] mm: abstract vma_address() and introduce vma_anon_address()
* [PATCH 04/15] mm: update print_bad_page_map() to show virtual page index
* [PATCH 05/15] mm: introduce and use vma_filebacked_address()
* [PATCH 06/15] mm: propagate VMA virtual page offset on map, remap, split + merge
* [PATCH 07/15] mm/rmap: track whether the page VMA mapped walk is anonymous
* [PATCH 08/15] mm: introduce and use linear_folio_page_index()
* [PATCH 09/15] mm/rmap: use virt pgoff for MAP_PRIVATE file-backed anon folios
* [PATCH 10/15] tools/testing/vma: expand VMA merge tests to assert virt pgoff
* [PATCH 11/15] tools/testing/selftests/mm: test virtual page offset merge behaviour
* [PATCH 12/15] mm/vma: only permit MAP_PRIVATE /dev/zero to be mapped anonymous
* [PATCH 13/15] mm/vma: make MAP_PRIVATE-mapped /dev/zero mappings truly anonymous
* [PATCH 14/15] tools/testing/vma: add test to assert MAP_PRIVATE-/dev/zero is anon
* [PATCH 15/15] tools/testing/selftests/mm: add MAP_PRIVATE-/dev/zero merge tests
and found the following issue:
general protection fault in mapping_wrprotect_range_one
Full report is available here:
https://ci.syzbot.org/series/b5c827e8-78a4-494c-b925-417c34a60e85
***
general protection fault in mapping_wrprotect_range_one
tree: mm-new
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/akpm/mm.git
base: 5093dba1014c1d7f7e247fd118f0fa8f22136046
arch: amd64
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
config: https://ci.syzbot.org/builds/0d856612-f1b4-4e6e-86af-4ed3215225aa/config
syz repro: https://ci.syzbot.org/findings/3484dc14-c12f-477e-b14a-6b249c47b2fd/syz_repro
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 UID: 0 PID: 32 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events fb_deferred_io_work
RIP: 0010:folio_test_anon include/linux/page-flags.h:718 [inline]
RIP: 0010:mapping_wrprotect_range_one+0x147/0x230 mm/rmap.c:1246
Code: 7c 24 40 49 8d 7f 28 ba 18 00 00 00 31 f6 e8 e0 2e 14 00 48 c7 84 24 80 00 00 00 01 00 00 00 49 83 c6 18 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 ea 2b 14 00 4d 8b 36 44 89 f6 83
RSP: 0018:ffffc90000a777c0 EFLAGS: 00010206
RAX: 0000000000000003 RBX: ffffc90000a779e0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90000a77840
RBP: ffffc90000a778e0 R08: ffffc90000a7783f R09: 0000000000000000
R10: ffffc90000a77828 R11: fffff5200014ef08 R12: dffffc0000000000
R13: 1ffff9200014eefc R14: 0000000000000018 R15: ffffc90000a77800
FS: 0000000000000000(0000) GS:ffff8882a920c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f84a91e9c38 CR3: 000000000e746000 CR4: 00000000000006f0
Call Trace:
<TASK>
__rmap_walk_file+0x4cd/0x6a0 mm/rmap.c:3116
mapping_wrprotect_range+0x110/0x180 mm/rmap.c:1294
fb_deferred_io_work+0x15a/0x310 drivers/video/fbdev/core/fb_defio.c:399
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:folio_test_anon include/linux/page-flags.h:718 [inline]
RIP: 0010:mapping_wrprotect_range_one+0x147/0x230 mm/rmap.c:1246
Code: 7c 24 40 49 8d 7f 28 ba 18 00 00 00 31 f6 e8 e0 2e 14 00 48 c7 84 24 80 00 00 00 01 00 00 00 49 83 c6 18 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 ea 2b 14 00 4d 8b 36 44 89 f6 83
RSP: 0018:ffffc90000a777c0 EFLAGS: 00010206
RAX: 0000000000000003 RBX: ffffc90000a779e0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90000a77840
RBP: ffffc90000a778e0 R08: ffffc90000a7783f R09: 0000000000000000
R10: ffffc90000a77828 R11: fffff5200014ef08 R12: dffffc0000000000
R13: 1ffff9200014eefc R14: 0000000000000018 R15: ffffc90000a77800
FS: 0000000000000000(0000) GS:ffff8882a920c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000025d35e991000 CR3: 0000000110c34000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
0: 7c 24 jl 0x26
2: 40 rex
3: 49 8d 7f 28 lea 0x28(%r15),%rdi
7: ba 18 00 00 00 mov $0x18,%edx
c: 31 f6 xor %esi,%esi
e: e8 e0 2e 14 00 call 0x142ef3
13: 48 c7 84 24 80 00 00 movq $0x1,0x80(%rsp)
1a: 00 01 00 00 00
1f: 49 83 c6 18 add $0x18,%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 f7 mov %r14,%rdi
34: e8 ea 2b 14 00 call 0x142c23
39: 4d 8b 36 mov (%r14),%r14
3c: 44 89 f6 mov %r14d,%esi
3f: 83 .byte 0x83
***
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.
To test a patch for this bug, please reply with `#syz test`
(should be on a separate line).
The patch should be attached to the email.
Note: arguments like custom git repos and branches are not supported.
prev parent reply other threads:[~2026-07-18 6:47 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-17 18:19 [PATCH 00/15] mm/rmap: index MAP_PRIVATE file-backed folios by virt pgoff Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 01/15] mm/vma: introduce VMA virtual page offset field and add helpers Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 02/15] mm: introduce linear_virt_page_index() Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 03/15] mm: abstract vma_address() and introduce vma_anon_address() Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 04/15] mm: update print_bad_page_map() to show virtual page index Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 05/15] mm: introduce and use vma_filebacked_address() Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 06/15] mm: propagate VMA virtual page offset on map, remap, split + merge Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 07/15] mm/rmap: track whether the page VMA mapped walk is anonymous Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 08/15] mm: introduce and use linear_folio_page_index() Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 09/15] mm/rmap: use virt pgoff for MAP_PRIVATE file-backed anon folios Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 10/15] tools/testing/vma: expand VMA merge tests to assert virt pgoff Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 11/15] tools/testing/selftests/mm: test virtual page offset merge behaviour Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 12/15] mm/vma: only permit MAP_PRIVATE /dev/zero to be mapped anonymous Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 13/15] mm/vma: make MAP_PRIVATE-mapped /dev/zero mappings truly anonymous Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 14/15] tools/testing/vma: add test to assert MAP_PRIVATE-/dev/zero is anon Lorenzo Stoakes (ARM)
2026-07-17 18:19 ` [PATCH 15/15] tools/testing/selftests/mm: add MAP_PRIVATE-/dev/zero merge tests Lorenzo Stoakes (ARM)
2026-07-18 6:47 ` syzbot ci [this message]
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