#syz test
On Sat, Nov 23, 2024 at 1:01 PM syzbot <syzbot+9f9a7f73fb079b2387a6@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
Hello,
syzbot found the following issue on:
HEAD commit: 9fb2cfa4635a Merge tag 'pull-ufs' of git://git.kernel.org/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10042930580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c4515f1b6a4e50b7
dashboard link: https://syzkaller.appspot.com/bug?extid=9f9a7f73fb079b2387a6
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=105ff2e8580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7c0c61a15f60/disk-9fb2cfa4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3363d84eeb74/vmlinux-9fb2cfa4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2b1a270af550/bzImage-9fb2cfa4.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9f9a7f73fb079b2387a6@xxxxxxxxxxxxxxxxxxxxxxxxx
madvise_pageout_page_range mm/madvise.c:609 [inline]
madvise_pageout+0x326/0x820 mm/madvise.c:636
madvise_vma_behavior+0x58c/0x19e0 mm/madvise.c:1045
madvise_walk_vmas+0x1cf/0x2c0 mm/madvise.c:1274
do_madvise+0x29d/0x700 mm/madvise.c:1461
__do_sys_madvise mm/madvise.c:1477 [inline]
__se_sys_madvise mm/madvise.c:1475 [inline]
__x64_sys_madvise+0xa9/0x110 mm/madvise.c:1475
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
------------[ cut here ]------------
kernel BUG at include/linux/page-flags.h:309!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 7269 Comm: syz.1.183 Not tainted 6.12.0-syzkaller-00233-g9fb2cfa4635a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:const_folio_flags.constprop.0+0x12e/0x150 include/linux/page-flags.h:309
Code: 86 cb ff e8 f4 86 cb ff 48 8d 45 ff 48 39 c3 0f 84 38 ff ff ff e8 e2 86 cb ff 48 c7 c6 00 19 58 8b 48 89 df e8 e3 4b 11 00 90 <0f> 0b e8 6b 0d 2d 00 e9 f1 fe ff ff e8 61 0d 2d 00 eb a3 48 89 df
RSP: 0018:ffffc9000c55ee30 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffea0000496f80 RCX: ffffc9000c55ecd8
RDX: ffff88805f401e00 RSI: ffffffff81c1362d RDI: ffff88805f402244
RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff203a591
R10: ffffffff901d2c8f R11: 0000000000000001 R12: 00000000000014df
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920018abdf4
FS: 00007f08b31bc6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0025ff000 CR3: 00000000341ce000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
folio_test_locked include/linux/page-flags.h:509 [inline]
next_uptodate_folio+0xac/0x4b0 mm/filemap.c:3505
filemap_map_pages+0x1c6/0x16a0 mm/filemap.c:3647
do_fault_around mm/memory.c:5255 [inline]
do_read_fault mm/memory.c:5288 [inline]
do_fault mm/memory.c:5431 [inline]
do_pte_missing+0xdae/0x3e70 mm/memory.c:3965
handle_pte_fault mm/memory.c:5766 [inline]
__handle_mm_fault+0x100a/0x2a10 mm/memory.c:5909
handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6077
faultin_page mm/gup.c:1187 [inline]
__get_user_pages+0x8d9/0x3b50 mm/gup.c:1485
__get_user_pages_locked mm/gup.c:1751 [inline]
get_dump_page+0xfb/0x220 mm/gup.c:2269
dump_user_range+0x135/0x8c0 fs/coredump.c:943
elf_core_dump+0x2766/0x3840 fs/binfmt_elf.c:2121
do_coredump+0x2c42/0x4160 fs/coredump.c:758
get_signal+0x237c/0x26d0 kernel/signal.c:2903
arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x1000
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 002b:000000000000010c EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007f08b41363b8 RCX: 00007f08b3f7e759
RDX: ffffffffff600000 RSI: 0000000000000104 RDI: 8000000000000000
RBP: 00007f08b3ff175e R08: 0000000100000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f08b41363b8 R15: 00007fff7656a008
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:const_folio_flags.constprop.0+0x12e/0x150 include/linux/page-flags.h:309
Code: 86 cb ff e8 f4 86 cb ff 48 8d 45 ff 48 39 c3 0f 84 38 ff ff ff e8 e2 86 cb ff 48 c7 c6 00 19 58 8b 48 89 df e8 e3 4b 11 00 90 <0f> 0b e8 6b 0d 2d 00 e9 f1 fe ff ff e8 61 0d 2d 00 eb a3 48 89 df
RSP: 0018:ffffc9000c55ee30 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffea0000496f80 RCX: ffffc9000c55ecd8
RDX: ffff88805f401e00 RSI: ffffffff81c1362d RDI: ffff88805f402244
RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff203a591
R10: ffffffff901d2c8f R11: 0000000000000001 R12: 00000000000014df
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920018abdf4
FS: 00007f08b31bc6c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff76568ff8 CR3: 00000000341ce000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
--
You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion visit https://groups.google.com/d/msgid/syzkaller-bugs/674184c9.050a0220.1cc393.0001.GAE%40google.com.
From 26b892d116fabd0395de4dcddbeb2dfdbd4a7426 Mon Sep 17 00:00:00 2001
From: Suraj Sonawane <surajsonawane0215@xxxxxxxxx>
Date: Mon, 25 Nov 2024 12:22:12 +0530
Subject: [PATCH] fix kernel BUG in const_folio_flags (2)
syz test
Signed-off-by: Suraj Sonawane <surajsonawane0215@xxxxxxxxx>
---
include/linux/page-flags.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 908ee0aad..ab562ff45 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -306,6 +306,12 @@ static const unsigned long *const_folio_flags(const struct folio *folio,
{
const struct page *page = &folio->page;
+ /* Add a check for n to ensure it's within bounds. */
+ if (n >= folio_nr_pages(folio)) {
+ pr_err("Invalid folio index: n=%u, folio_nr_pages=%u\n", n, folio_nr_pages(folio));
+ return -EINVAL;
+ }
+
VM_BUG_ON_PGFLAGS(PageTail(page), page);
VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page);
return &page[n].flags;
--
2.34.1
