Subject: [syzbot] [bpf?] BUG: unable to handle kernel paging request in jhash

From: syzbot <[email-masked]>
Date: Sat, 06 Apr 2024 22:59:15 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    f99c5f563c17 Merge tag 'nf-24-03-21' of git://git.kernel.o..
git tree:       net
console+strace: https://syzkaller.appspot.com/x/log.txt?x=105e88a9180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440
dashboard link: https://syzkaller.appspot.com/bug?extid=6592955f6080eeb2160f
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=134c0cad180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11faf09d180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/65d3f3eb786e/disk-f99c5f56.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/799cf7f28ff8/vmlinux-f99c5f56.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ab26c60c3845/bzImage-f99c5f56.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

==================================================================
BUG: KASAN: stack-out-of-bounds in __get_unaligned_cpu32 include/linux/unaligned/packed_struct.h:19 [inline]
BUG: KASAN: stack-out-of-bounds in jhash+0x200/0x740 include/linux/jhash.h:82
Read of size 4 at addr ffffc9000a42eb20 by task kworker/u8:8/2470

CPU: 0 PID: 2470 Comm: kworker/u8:8 Not tainted 6.8.0-syzkaller-05271-gf99c5f563c17 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 __get_unaligned_cpu32 include/linux/unaligned/packed_struct.h:19 [inline]
 jhash+0x200/0x740 include/linux/jhash.h:82
 hash+0x339/0x410 kernel/bpf/bloom_filter.c:31
 bloom_map_peek_elem+0xb2/0x1b0 kernel/bpf/bloom_filter.c:43
 bpf_prog_00798911c748094f+0x42/0x46
 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
 __bpf_prog_run include/linux/filter.h:657 [inline]
 bpf_prog_run include/linux/filter.h:664 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
 bpf_trace_run8+0x2ec/0x500 kernel/trace/bpf_trace.c:2426
 __bpf_trace_jbd2_handle_stats+0x47/0x60 include/trace/events/jbd2.h:210
 trace_jbd2_handle_stats include/trace/events/jbd2.h:210 [inline]
 jbd2_journal_stop+0xd3d/0xdc0 fs/jbd2/transaction.c:1869
 __ext4_journal_stop+0xfd/0x1a0 fs/ext4/ext4_jbd2.c:134
 ext4_do_writepages+0x2d24/0x3ca0 fs/ext4/inode.c:2692
 ext4_writepages+0x204/0x3e0 fs/ext4/inode.c:2768
 do_writepages+0x3a4/0x670 mm/page-writeback.c:2553
 __writeback_single_inode+0x155/0xfd0 fs/fs-writeback.c:1650
 writeback_sb_inodes+0x8e4/0x1220 fs/fs-writeback.c:1941
 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2012
 wb_writeback+0x45b/0xc70 fs/fs-writeback.c:2119
 wb_check_old_data_flush fs/fs-writeback.c:2223 [inline]
 wb_do_writeback fs/fs-writeback.c:2276 [inline]
 wb_workfn+0xb7c/0x1070 fs/fs-writeback.c:2304
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

The buggy address belongs to stack of task kworker/u8:8/2470
 and is located at offset 0 in frame:
 bpf_trace_run8+0x0/0x500

This frame has 1 object:
 [32, 96) 'args'

The buggy address belongs to the virtual mapping at
 [ffffc9000a428000, ffffc9000a431000) created by:
 copy_process+0x5d1/0x3df0 kernel/fork.c:2219

The buggy address belongs to the physical page:
page:ffffea0000a37d80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28df6
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_ZERO), pid 60, tgid 60 (kworker/u8:4), ts 12699826929, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
 prep_new_page mm/page_alloc.c:1540 [inline]
 get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
 __alloc_pages+0x256/0x680 mm/page_alloc.c:4569
 alloc_pages_mpol+0x3de/0x650 mm/mempolicy.c:2133
 vm_area_alloc_pages mm/vmalloc.c:3135 [inline]
 __vmalloc_area_node mm/vmalloc.c:3211 [inline]
 __vmalloc_node_range+0x9a4/0x14a0 mm/vmalloc.c:3392
 alloc_thread_stack_node kernel/fork.c:309 [inline]
 dup_task_struct+0x3e9/0x7d0 kernel/fork.c:1114
 copy_process+0x5d1/0x3df0 kernel/fork.c:2219
 kernel_clone+0x21e/0x8d0 kernel/fork.c:2796
 user_mode_thread+0x132/0x1a0 kernel/fork.c:2874
 call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:172
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
page_owner free stack trace missing

Memory state around the buggy address:
 ffffc9000a42ea00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000a42ea80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000a42eb00: 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 00 00 00
                               ^
 ffffc9000a42eb80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000a42ec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

---
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