Re: [syzbot] [mm?] kernel BUG in sg_init_one

syzbot
2024-03-18T20:52:03Z

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in __kmap_to_page

------------[ cut here ]------------
WARNING: CPU: 0 PID: 3529 at mm/highmem.c:167 __kmap_to_page+0x100/0x194 mm/highmem.c:167
Modules linked in:
Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 0 PID: 3529 Comm: syz-executor.0 Not tainted 6.8.0-syzkaller #0
Hardware name: ARM-Versatile Express
Backtrace:
[<8185fe64>] (dump_backtrace) from [<8185ff60>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:256)
r7:00000000 r6:82622e44 r5:00000000 r4:81fc00fc
[<8185ff48>] (show_stack) from [<8187d720>] (__dump_stack lib/dump_stack.c:88 [inline])
[<8185ff48>] (show_stack) from [<8187d720>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:114)
[<8187d6cc>] (dump_stack_lvl) from [<8187d760>] (dump_stack+0x18/0x1c lib/dump_stack.c:123)
r5:00000000 r4:82857d18
[<8187d748>] (dump_stack) from [<81860a08>] (panic+0x120/0x358 kernel/panic.c:348)
[<818608e8>] (panic) from [<80243844>] (check_panic_on_warn kernel/panic.c:241 [inline])
[<818608e8>] (panic) from [<80243844>] (print_tainted+0x0/0xa0 kernel/panic.c:236)
r3:8260c584 r2:00000001 r1:81fa8e48 r0:81fb09f0
r7:80477264
[<802437d0>] (check_panic_on_warn) from [<80243a38>] (__warn+0x7c/0x180 kernel/panic.c:694)
[<802439bc>] (__warn) from [<80243cb4>] (warn_slowpath_fmt+0x178/0x1f4 kernel/panic.c:719)
r8:00000009 r7:81fd71bc r6:df9b1bf4 r5:83682400 r4:00000000
[<80243b40>] (warn_slowpath_fmt) from [<80477264>] (__kmap_to_page+0x100/0x194 mm/highmem.c:167)
r10:00000000 r9:ff7e7f14 r8:83e402c0 r7:dedf0b48 r6:800fd004 r5:ffefd000
r4:7fefd004
[<80477164>] (__kmap_to_page) from [<804c248c>] (kmap_to_page include/linux/highmem-internal.h:63 [inline])
[<80477164>] (__kmap_to_page) from [<804c248c>] (zswap_decompress+0xc0/0x23c mm/zswap.c:1090)
r9:ff7e7f14 r8:83e402c0 r7:dedf0b48 r6:ffefd004 r5:840fb8e8 r4:ff7e7ef4
[<804c23cc>] (zswap_decompress) from [<804c449c>] (zswap_load+0x15c/0x198 mm/zswap.c:1638)
r9:846e3240 r8:846e3240 r7:846e3244 r6:dedf0b48 r5:00000010 r4:840fb8e8
[<804c4340>] (zswap_load) from [<804b9644>] (swap_read_folio+0xa8/0x498 mm/page_io.c:518)
r9:8420fa00 r8:83682400 r7:00000000 r6:df9b1d4c r5:00000000 r4:dedf0b48
[<804b959c>] (swap_read_folio) from [<804bb064>] (swap_cluster_readahead+0x1c4/0x34c mm/swap_state.c:684)
r10:00000000 r9:00000017 r8:df9b1d4b r7:00000000 r6:00000000 r5:00100cca
r4:00000010
[<804baea0>] (swap_cluster_readahead) from [<804bb3b8>] (swapin_readahead+0x68/0x4a8 mm/swap_state.c:904)
r10:df9b1eb8 r9:00000000 r8:00100cca r7:8371e2a0 r6:00000012 r5:00000000
r4:00000001
[<804bb350>] (swapin_readahead) from [<8047cde0>] (do_swap_page+0x200/0xcc4 mm/memory.c:4046)
r10:00000040 r9:00000000 r8:8420fa00 r7:8371e2a0 r6:00000012 r5:00000000
r4:df9b1eb8
[<8047cbe0>] (do_swap_page) from [<8047e6c4>] (handle_pte_fault mm/memory.c:5301 [inline])
[<8047cbe0>] (do_swap_page) from [<8047e6c4>] (__handle_mm_fault mm/memory.c:5439 [inline])
[<8047cbe0>] (do_swap_page) from [<8047e6c4>] (handle_mm_fault+0x3d8/0x12b8 mm/memory.c:5604)
r10:00000040 r9:83dfb900 r8:83682400 r7:8371e2a0 r6:001403b8 r5:83682400
r4:00001254
[<8047e2ec>] (handle_mm_fault) from [<80215da8>] (do_page_fault+0x1c8/0x3a8 arch/arm/mm/fault.c:292)
r10:00000007 r9:83dfb900 r8:83682400 r7:00000207 r6:00000254 r5:001403b8
r4:df9b1fb0
[<80215be0>] (do_page_fault) from [<80216170>] (do_DataAbort+0x38/0xa8 arch/arm/mm/fault.c:558)
r10:7eded670 r9:00000000 r8:80215be0 r7:df9b1fb0 r6:001403b8 r5:00000207
r4:8261d0e0
[<80216138>] (do_DataAbort) from [<80200e3c>] (__dabt_usr+0x5c/0x60 arch/arm/kernel/entry-armv.S:427)
Exception stack(0xdf9b1fb0 to 0xdf9b1ff8)
1fa0: 00000000 00000000 00000000 00000000
1fc0: 00000002 7eded61c 00000000 000001f4 00140000 00000000 7eded670 00001238
1fe0: 00000000 7eded5a8 00000001 00021804 60000010 ffffffff
r8:824a9044 r7:83682400 r6:ffffffff r5:60000010 r4:00021804
Rebooting in 86400 seconds..

Tested on:

commit: e5eb28f6 Merge tag 'mm-nonmm-stable-2024-03-14-09-36' ..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1491ea6e180000
kernel config: https://syzkaller.appspot.com/x/.config?x=19bb57c23dffc38e
dashboard link: https://syzkaller.appspot.com/bug?extid=adbc983a1588b7805de3
compiler: arm-linux-gnueabi-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm
patch: https://syzkaller.appspot.com/x/patch.diff?x=12651546180000