[syzbot] [mm?] UBSAN: shift-out-of-bounds in do_shrink_slab

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    6dc544b66971 Add linux-next specific files for 20240528
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14c7f806980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6a363b35598e573d
dashboard link: https://syzkaller.appspot.com/bug?extid=981b8efffb3d71c46bef
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/334699ab67f8/disk-6dc544b6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4ca32b2218ce/vmlinux-6dc544b6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/400bc5f019b3/bzImage-6dc544b6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+981b8efffb3d71c46bef@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
UBSAN: shift-out-of-bounds in mm/shrinker.c:406:18
shift exponent -1 is negative
CPU: 0 PID: 5278 Comm: syz-executor.1 Not tainted 6.10.0-rc1-next-20240528-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468
 do_shrink_slab+0xe26/0x1160 mm/shrinker.c:406
 shrink_slab_memcg mm/shrinker.c:548 [inline]
 shrink_slab+0x87c/0x14d0 mm/shrinker.c:626
 shrink_node_memcgs mm/vmscan.c:5923 [inline]
 shrink_node+0xb82/0x4150 mm/vmscan.c:5961
 shrink_zones mm/vmscan.c:6205 [inline]
 do_try_to_free_pages+0x789/0x1cb0 mm/vmscan.c:6267
 try_to_free_mem_cgroup_pages+0x48f/0xb10 mm/vmscan.c:6598
 try_charge_memcg+0x704/0x1850 mm/memcontrol.c:2946
 obj_cgroup_charge_pages mm/memcontrol.c:3420 [inline]
 __memcg_kmem_charge_page+0xe2/0x250 mm/memcontrol.c:3446
 __alloc_pages_noprof+0x28c/0x6c0 mm/page_alloc.c:4712
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 bpf_ringbuf_area_alloc kernel/bpf/ringbuf.c:122 [inline]
 bpf_ringbuf_alloc+0xcb/0x420 kernel/bpf/ringbuf.c:170
 ringbuf_map_alloc+0x1d7/0x2f0 kernel/bpf/ringbuf.c:204
 map_create+0x90c/0x1200 kernel/bpf/syscall.c:1333
 __sys_bpf+0x6d1/0x810 kernel/bpf/syscall.c:5669
 __do_sys_bpf kernel/bpf/syscall.c:5794 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5792 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5792
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efea107cee9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efea1de60c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007efea11b3fa0 RCX: 00007efea107cee9
RDX: 0000000000000048 RSI: 00000000200002c0 RDI: 0000000000000000
RBP: 00007efea10c947f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007efea11b3fa0 R15: 00007fff6651b5d8
 </TASK>
---[ end trace ]---


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