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BUG: KASAN: stack-out-of-bounds in should_fault_in_pages fs/gfs2/file.c:784 [inline]
BUG: KASAN: stack-out-of-bounds in gfs2_file_buffered_write+0x4c8/0x874 fs/gfs2/file.c:1069
Read of size 8 at addr ffff800020787b30 by task syz.4.197/4798

CPU: 0 PID: 4798 Comm: syz.4.197 Not tainted 5.15.172-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x174/0x1e4 mm/kasan/report.c:451
 __asan_report_load8_noabort+0x44/0x50 mm/kasan/report_generic.c:309
 should_fault_in_pages fs/gfs2/file.c:784 [inline]
 gfs2_file_buffered_write+0x4c8/0x874 fs/gfs2/file.c:1069
 gfs2_file_write_iter+0x3b8/0xc80 fs/gfs2/file.c:1165
 call_write_iter include/linux/fs.h:2174 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x884/0xb44 fs/read_write.c:594
 ksys_write+0x15c/0x26c fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:656
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584


addr ffff800020787b30 is located in stack of task syz.4.197/4798 at offset 48 in frame:
 percpu_up_read include/linux/percpu-rwsem.h:118 [inline]
 __sb_end_write include/linux/fs.h:1808 [inline]
 vfs_write+0x0/0xb44 include/linux/fs.h:3058

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

Memory state around the buggy address:
 ffff800020787a00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
 ffff800020787a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff800020787b00: f1 f1 f1 f1 00 00 f2 f2 00 00 00 00 00 00 f2 f2
                                     ^
 ffff800020787b80: f2 f2 00 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00
 ffff800020787c00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
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