[syzbot] [fs?] [mm?] kernel BUG in __filemap_add_folio

[syzbot <syzbot+4d3cc33ef7a77041efa6@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    ac71fabf1567 gcc-15: work around sequence-point warning
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1269b204580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=68d9f79fc685cd4
dashboard link: https://syzkaller.appspot.com/bug?extid=4d3cc33ef7a77041efa6
compiler:       Debian clang version 15.0.6, Debian LLD 15.0.6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10b2cc70580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14a91ccc580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c03ec6447343/disk-ac71fabf.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e02e7fb54511/vmlinux-ac71fabf.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7d53dcc94699/bzImage-ac71fabf.xz

The issue was bisected to:

commit 47dd67532303803a87f43195e088b3b4bcf0454d
Author: Luis Chamberlain <mcgrof@kernel.org>
Date:   Fri Feb 21 22:38:22 2025 +0000

    block/bdev: lift block size restrictions to 64k

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=11d62c70580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=13d62c70580000
console output: https://syzkaller.appspot.com/x/log.txt?x=15d62c70580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4d3cc33ef7a77041efa6@syzkaller.appspotmail.com
Fixes: 47dd67532303 ("block/bdev: lift block size restrictions to 64k")

 __handle_mm_fault mm/memory.c:6140 [inline]
 handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309
 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x45b/0x920 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
------------[ cut here ]------------
kernel BUG at mm/filemap.c:868!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 5909 Comm: syz-executor413 Not tainted 6.15.0-rc2-syzkaller-00493-gac71fabf1567 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__filemap_add_folio+0x1554/0x16c0 mm/filemap.c:867
Code: e9 c5 ff 4c 89 e7 48 c7 c6 80 0e 54 8c e8 44 43 12 00 90 0f 0b e8 cc e9 c5 ff 4c 89 e7 48 c7 c6 00 05 54 8c e8 2d 43 12 00 90 <0f> 0b e8 b5 e9 c5 ff 4c 89 e7 48 c7 c6 80 0e 54 8c e8 16 43 12 00
RSP: 0018:ffffc90004087300 EFLAGS: 00010246
RAX: ba56fbab94ec7e00 RBX: 0000000000000004 RCX: ffffffff93686020
RDX: dffffc0000000000 RSI: ffffffff8e6497f7 RDI: 0000000000000001
RBP: ffffc900040874b0 R08: ffffffff905fe577 R09: 1ffffffff20bfcae
R10: dffffc0000000000 R11: fffffbfff20bfcaf R12: ffffea0001ededc0
R13: ffffc90004087400 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000555577940380(0000) GS:ffff88812509a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb2a265a1f0 CR3: 000000007eb78000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 filemap_add_folio+0x157/0x380 mm/filemap.c:969
 page_cache_ra_unbounded+0x40c/0x820 mm/readahead.c:275
 do_sync_mmap_readahead+0x3e6/0x6c0 mm/filemap.c:-1
 filemap_fault+0x763/0x13d0 mm/filemap.c:3403
 __do_fault+0x137/0x390 mm/memory.c:5098
 do_shared_fault mm/memory.c:5582 [inline]
 do_fault mm/memory.c:5656 [inline]
 do_pte_missing mm/memory.c:4160 [inline]
 handle_pte_fault+0xfcc/0x61c0 mm/memory.c:5997
 __handle_mm_fault mm/memory.c:6140 [inline]
 handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309
 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x45b/0x920 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fb2a25adba4
Code: 2d 41 b8 13 00 00 00 bf 09 00 00 00 bb 03 00 00 00 e8 b0 14 03 00 ba 71 12 08 40 bf 10 00 00 00 48 b8 00 01 00 00 00 20 00 00 <48> c7 00 00 00 01 00 48 8b 35 1e 95 0a 00 48 89 c1 31 c0 e8 84 14
RSP: 002b:00007ffd9b4d3c20 EFLAGS: 00010217
RAX: 0000200000000100 RBX: 0000000000000003 RCX: 00007fb2a25df059
RDX: 0000000040081271 RSI: 0000000000b36000 RDI: 0000000000000010
RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000000000013 R11: 0000000000000216 R12: 00007ffd9b4d3c4c
R13: 00007ffd9b4d3c60 R14: 00007ffd9b4d3ca0 R15: 0000000000000008
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__filemap_add_folio+0x1554/0x16c0 mm/filemap.c:867
Code: e9 c5 ff 4c 89 e7 48 c7 c6 80 0e 54 8c e8 44 43 12 00 90 0f 0b e8 cc e9 c5 ff 4c 89 e7 48 c7 c6 00 05 54 8c e8 2d 43 12 00 90 <0f> 0b e8 b5 e9 c5 ff 4c 89 e7 48 c7 c6 80 0e 54 8c e8 16 43 12 00
RSP: 0018:ffffc90004087300 EFLAGS: 00010246
RAX: ba56fbab94ec7e00 RBX: 0000000000000004 RCX: ffffffff93686020
RDX: dffffc0000000000 RSI: ffffffff8e6497f7 RDI: 0000000000000001
RBP: ffffc900040874b0 R08: ffffffff905fe577 R09: 1ffffffff20bfcae
R10: dffffc0000000000 R11: fffffbfff20bfcaf R12: ffffea0001ededc0
R13: ffffc90004087400 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000555577940380(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb2a265a1f0 CR3: 000000007eb78000 CR4: 0000000000350ef0


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