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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+0x576/0x900 fs/gfs2/file.c:1070
Read of size 8 at addr ffffc9000343f350 by task syz.4.16/4370

CPU: 1 PID: 4370 Comm: syz.4.16 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 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+0x576/0x900 fs/gfs2/file.c:1070
 gfs2_file_write_iter+0x467/0x11d0 fs/gfs2/file.c:1166
 __kernel_write+0x4f9/0x930 fs/read_write.c:539
 __dump_emit+0x243/0x360 fs/coredump.c:943
 elf_core_dump+0x27b4/0x3530 fs/binfmt_elf.c:2237
 do_coredump+0x1419/0x2960 fs/coredump.c:894
 get_signal+0x40a/0x12c0 kernel/signal.c:2886
 arch_do_signal_or_restart+0xc1/0x1300 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:1504
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f78df4c06b7
Code: 88 15 42 60 ec 00 88 05 3f 60 ec 00 c3 50 48 8d 35 e9 28 1c 00 48 8d 3d ef 28 1c 00 31 c0 e8 20 f7 ff ff 53 89 fb 48 83 ec 10 <64> 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8
RSP: 002b:00007f78dd848120 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f78df6006c9
RDX: 00007f78dd848140 RSI: 00007f78dd848270 RDI: 000000000000000b
RBP: 00007f78df682f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f78df857038 R14: 00007f78df856fa0 R15: 00007ffc9ec0ef68
 </TASK>


addr ffffc9000343f350 is located in stack of task syz.4.16/4370 at offset 48 in frame:
 __kernel_write+0x0/0x930

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

Memory state around the buggy address:
 ffffc9000343f200: 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00
 ffffc9000343f280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000343f300: 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 00 00 00 00
                                                 ^
 ffffc9000343f380: 00 00 f2 f2 f2 f2 00 00 00 00 00 f3 f3 f3 f3 f3
 ffffc9000343f400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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