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BUG: KASAN: stack-out-of-bounds in should_fault_in_pages fs/gfs2/file.c:785 [inline]
BUG: KASAN: stack-out-of-bounds in gfs2_file_buffered_write+0x56a/0x910 fs/gfs2/file.c:1070
Read of size 8 at addr ffffc900034bf350 by task syz.3.38/4455

CPU: 0 PID: 4455 Comm: syz.3.38 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 should_fault_in_pages fs/gfs2/file.c:785 [inline]
 gfs2_file_buffered_write+0x56a/0x910 fs/gfs2/file.c:1070
 gfs2_file_write_iter+0x4a9/0x11f0 fs/gfs2/file.c:1166
 __kernel_write+0x522/0x980 fs/read_write.c:539
 __dump_emit+0x258/0x380 fs/coredump.c:943
 elf_core_dump+0x2777/0x3530 fs/binfmt_elf.c:2237
 do_coredump+0x14e8/0x2a40 fs/coredump.c:894
 get_signal+0x531/0x12e0 kernel/signal.c:2887
 arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1499
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f0b77d52e61
Code: 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 <c3> 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f0b77fdb090 RCX: 00007f0b77d52e59
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f0b77de8e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f0b77fdb128 R14: 00007f0b77fdb090 R15: 00007fff6e7f0828
 </TASK>


addr ffffc900034bf350 is located in stack of task syz.3.38/4455 at offset 48 in frame:
 new_sync_read fs/read_write.c:405 [inline]
 __kernel_write+0x0/0x980 fs/read_write.c:485

this frame has 3 objects:
 [32, 48) 'iov'
 [64, 112) 'kiocb'
 [144, 184) 'iter'

Memory state around the buggy address:
 ffffc900034bf200: 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00
 ffffc900034bf280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900034bf300: 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 00 00 00 00
                                                 ^
 ffffc900034bf380: 00 00 f2 f2 f2 f2 00 00 00 00 00 f3 f3 f3 f3 f3
 ffffc900034bf400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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