WARNING in get_pte_pfn

syzbot syzbot 3 participants 5 messages Dec 22, 2023 – Dec 23, 2023

Subsystems (4)

Memory management MGLRU io_uring MM reclaim

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syzbot

author syzbot

2023-12-22 08:11 UTC #0 lore raw

Hello,

syzbot found the following issue on:

HEAD commit:    0e389834672c Merge tag 'for-6.7-rc5-tag' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1454824ee80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f21aff374937e60e
dashboard link: https://syzkaller.appspot.com/bug?extid=03fd9b3f71641f0ebf2d
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13b4ef49e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=118314d6e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e58cd74e152a/disk-0e389834.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/45d17ccb34bc/vmlinux-0e389834.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9b7105d4e08/bzImage-0e389834.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by [email protected]

------------[ cut here ]------------
WARNING: CPU: 1 PID: 5066 at mm/vmscan.c:3242 get_pte_pfn+0x1b5/0x3f0 mm/vmscan.c:3242
Modules linked in:
CPU: 1 PID: 5066 Comm: syz-executor668 Not tainted 6.7.0-rc5-syzkaller-00270-g0e389834672c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:get_pte_pfn+0x1b5/0x3f0 mm/vmscan.c:3242
Code: f3 74 2a e8 6d 78 cb ff 31 ff 48 b8 00 00 00 00 00 00 00 02 48 21 c5 48 89 ee e8 e6 73 cb ff 48 85 ed 74 4e e8 4c 78 cb ff 90 <0f> 0b 90 48 c7 c3 ff ff ff ff e8 3c 78 cb ff 48 b8 00 00 00 00 00
RSP: 0018:ffffc900041e6878 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 000000000007891d RCX: ffffffff81bbf6e3
RDX: ffff88807d813b80 RSI: ffffffff81bbf684 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000000003 R12: 0000000000000200
R13: 1ffff9200083cd0f R14: 0000000000010b21 R15: 0000000020ffc000
FS:  0000555555f4d480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005fbfa000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lru_gen_look_around+0x70d/0x11a0 mm/vmscan.c:4001
 folio_referenced_one+0x5a2/0xf70 mm/rmap.c:843
 rmap_walk_anon+0x225/0x570 mm/rmap.c:2485
 rmap_walk mm/rmap.c:2562 [inline]
 rmap_walk mm/rmap.c:2557 [inline]
 folio_referenced+0x28a/0x4b0 mm/rmap.c:960
 folio_check_references mm/vmscan.c:829 [inline]
 shrink_folio_list+0x1ace/0x3f00 mm/vmscan.c:1160
 evict_folios+0x6e7/0x1b90 mm/vmscan.c:4499
 try_to_shrink_lruvec+0x638/0xa10 mm/vmscan.c:4704
 lru_gen_shrink_lruvec mm/vmscan.c:4849 [inline]
 shrink_lruvec+0x314/0x2990 mm/vmscan.c:5622
 shrink_node_memcgs mm/vmscan.c:5842 [inline]
 shrink_node+0x811/0x3710 mm/vmscan.c:5877
 shrink_zones mm/vmscan.c:6116 [inline]
 do_try_to_free_pages+0x36c/0x1940 mm/vmscan.c:6178
 try_to_free_mem_cgroup_pages+0x31a/0x770 mm/vmscan.c:6493
 try_charge_memcg+0x3d3/0x11f0 mm/memcontrol.c:2742
 obj_cgroup_charge_pages mm/memcontrol.c:3255 [inline]
 __memcg_kmem_charge_page+0xdd/0x2a0 mm/memcontrol.c:3281
 __alloc_pages+0x263/0x2420 mm/page_alloc.c:4585
 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133
 __get_free_pages+0xc/0x40 mm/page_alloc.c:4615
 io_mem_alloc+0x33/0x60 io_uring/io_uring.c:2789
 io_allocate_scq_urings io_uring/io_uring.c:3842 [inline]
 io_uring_create io_uring/io_uring.c:4019 [inline]
 io_uring_setup+0x13ed/0x2430 io_uring/io_uring.c:4131
 __do_sys_io_uring_setup io_uring/io_uring.c:4158 [inline]
 __se_sys_io_uring_setup io_uring/io_uring.c:4152 [inline]
 __x64_sys_io_uring_setup+0x98/0x140 io_uring/io_uring.c:4152
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f4b0e4778a9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 1a 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff814fe868 EFLAGS: 00000202 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4b0e4778a9
RDX: 0000000020000700 RSI: 0000000020000640 RDI: 0000000000005a19
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000020000700
R10: 00007fff814fe8d0 R11: 0000000000000202 R12: 0000000020000640
R13: 0000000000000000 R14: 0000000000005a19 R15: 0000000020000700
 </TASK>

---
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If the report is already addressed, let syzbot know by replying with:
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Jens Axboe

maintainer

2023-12-22 14:55 UTC #1 lore raw

Quoted 73 lines · syzbot

Hello,

syzbot found the following issue on:

HEAD commit:    0e389834672c Merge tag 'for-6.7-rc5-tag' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1454824ee80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f21aff374937e60e
dashboard link: https://syzkaller.appspot.com/bug?extid=03fd9b3f71641f0ebf2d
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13b4ef49e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=118314d6e80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by [email protected]

------------[ cut here ]------------
WARNING: CPU: 1 PID: 5066 at mm/vmscan.c:3242 get_pte_pfn+0x1b5/0x3f0 mm/vmscan.c:3242
Modules linked in:
CPU: 1 PID: 5066 Comm: syz-executor668 Not tainted 6.7.0-rc5-syzkaller-00270-g0e389834672c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:get_pte_pfn+0x1b5/0x3f0 mm/vmscan.c:3242
Code: f3 74 2a e8 6d 78 cb ff 31 ff 48 b8 00 00 00 00 00 00 00 02 48 21 c5 48 89 ee e8 e6 73 cb ff 48 85 ed 74 4e e8 4c 78 cb ff 90 <0f> 0b 90 48 c7 c3 ff ff ff ff e8 3c 78 cb ff 48 b8 00 00 00 00 00
RSP: 0018:ffffc900041e6878 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 000000000007891d RCX: ffffffff81bbf6e3
RDX: ffff88807d813b80 RSI: ffffffff81bbf684 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000000003 R12: 0000000000000200
R13: 1ffff9200083cd0f R14: 0000000000010b21 R15: 0000000020ffc000
FS:  0000555555f4d480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005fbfa000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lru_gen_look_around+0x70d/0x11a0 mm/vmscan.c:4001
 folio_referenced_one+0x5a2/0xf70 mm/rmap.c:843
 rmap_walk_anon+0x225/0x570 mm/rmap.c:2485
 rmap_walk mm/rmap.c:2562 [inline]
 rmap_walk mm/rmap.c:2557 [inline]
 folio_referenced+0x28a/0x4b0 mm/rmap.c:960
 folio_check_references mm/vmscan.c:829 [inline]
 shrink_folio_list+0x1ace/0x3f00 mm/vmscan.c:1160
 evict_folios+0x6e7/0x1b90 mm/vmscan.c:4499
 try_to_shrink_lruvec+0x638/0xa10 mm/vmscan.c:4704
 lru_gen_shrink_lruvec mm/vmscan.c:4849 [inline]
 shrink_lruvec+0x314/0x2990 mm/vmscan.c:5622
 shrink_node_memcgs mm/vmscan.c:5842 [inline]
 shrink_node+0x811/0x3710 mm/vmscan.c:5877
 shrink_zones mm/vmscan.c:6116 [inline]
 do_try_to_free_pages+0x36c/0x1940 mm/vmscan.c:6178
 try_to_free_mem_cgroup_pages+0x31a/0x770 mm/vmscan.c:6493
 try_charge_memcg+0x3d3/0x11f0 mm/memcontrol.c:2742
 obj_cgroup_charge_pages mm/memcontrol.c:3255 [inline]
 __memcg_kmem_charge_page+0xdd/0x2a0 mm/memcontrol.c:3281
 __alloc_pages+0x263/0x2420 mm/page_alloc.c:4585
 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133
 __get_free_pages+0xc/0x40 mm/page_alloc.c:4615
 io_mem_alloc+0x33/0x60 io_uring/io_uring.c:2789
 io_allocate_scq_urings io_uring/io_uring.c:3842 [inline]
 io_uring_create io_uring/io_uring.c:4019 [inline]
 io_uring_setup+0x13ed/0x2430 io_uring/io_uring.c:4131
 __do_sys_io_uring_setup io_uring/io_uring.c:4158 [inline]
 __se_sys_io_uring_setup io_uring/io_uring.c:4152 [inline]
 __x64_sys_io_uring_setup+0x98/0x140 io_uring/io_uring.c:4152
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f4b0e4778a9

Quoted 8 lines

Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 1a 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff814fe868 EFLAGS: 00000202 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4b0e4778a9
RDX: 0000000020000700 RSI: 0000000020000640 RDI: 0000000000005a19
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000020000700
R10: 00007fff814fe8d0 R11: 0000000000000202 R12: 0000000020000640
R13: 0000000000000000 R14: 0000000000005a19 R15: 0000000020000700
 </TASK>

Don't think this is io_uring related, test case looks like it's just setting up and tearing down big rings.

Signature · 1 line

Jens Axboe

Yu Zhao

2023-12-23 05:00 UTC #2 lore raw

Quoted 84 lines · Jens Axboe

Quoted 73 lines · syzbot

Hello,

syzbot found the following issue on:

HEAD commit:    0e389834672c Merge tag 'for-6.7-rc5-tag' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1454824ee80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f21aff374937e60e
dashboard link: https://syzkaller.appspot.com/bug?extid=03fd9b3f71641f0ebf2d
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13b4ef49e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=118314d6e80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by [email protected]

------------[ cut here ]------------
WARNING: CPU: 1 PID: 5066 at mm/vmscan.c:3242 get_pte_pfn+0x1b5/0x3f0 mm/vmscan.c:3242
Modules linked in:
CPU: 1 PID: 5066 Comm: syz-executor668 Not tainted 6.7.0-rc5-syzkaller-00270-g0e389834672c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:get_pte_pfn+0x1b5/0x3f0 mm/vmscan.c:3242
Code: f3 74 2a e8 6d 78 cb ff 31 ff 48 b8 00 00 00 00 00 00 00 02 48 21 c5 48 89 ee e8 e6 73 cb ff 48 85 ed 74 4e e8 4c 78 cb ff 90 <0f> 0b 90 48 c7 c3 ff ff ff ff e8 3c 78 cb ff 48 b8 00 00 00 00 00
RSP: 0018:ffffc900041e6878 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 000000000007891d RCX: ffffffff81bbf6e3
RDX: ffff88807d813b80 RSI: ffffffff81bbf684 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000000003 R12: 0000000000000200
R13: 1ffff9200083cd0f R14: 0000000000010b21 R15: 0000000020ffc000
FS:  0000555555f4d480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005fbfa000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lru_gen_look_around+0x70d/0x11a0 mm/vmscan.c:4001
 folio_referenced_one+0x5a2/0xf70 mm/rmap.c:843
 rmap_walk_anon+0x225/0x570 mm/rmap.c:2485
 rmap_walk mm/rmap.c:2562 [inline]
 rmap_walk mm/rmap.c:2557 [inline]
 folio_referenced+0x28a/0x4b0 mm/rmap.c:960
 folio_check_references mm/vmscan.c:829 [inline]
 shrink_folio_list+0x1ace/0x3f00 mm/vmscan.c:1160
 evict_folios+0x6e7/0x1b90 mm/vmscan.c:4499
 try_to_shrink_lruvec+0x638/0xa10 mm/vmscan.c:4704
 lru_gen_shrink_lruvec mm/vmscan.c:4849 [inline]
 shrink_lruvec+0x314/0x2990 mm/vmscan.c:5622
 shrink_node_memcgs mm/vmscan.c:5842 [inline]
 shrink_node+0x811/0x3710 mm/vmscan.c:5877
 shrink_zones mm/vmscan.c:6116 [inline]
 do_try_to_free_pages+0x36c/0x1940 mm/vmscan.c:6178
 try_to_free_mem_cgroup_pages+0x31a/0x770 mm/vmscan.c:6493
 try_charge_memcg+0x3d3/0x11f0 mm/memcontrol.c:2742
 obj_cgroup_charge_pages mm/memcontrol.c:3255 [inline]
 __memcg_kmem_charge_page+0xdd/0x2a0 mm/memcontrol.c:3281
 __alloc_pages+0x263/0x2420 mm/page_alloc.c:4585
 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133
 __get_free_pages+0xc/0x40 mm/page_alloc.c:4615
 io_mem_alloc+0x33/0x60 io_uring/io_uring.c:2789
 io_allocate_scq_urings io_uring/io_uring.c:3842 [inline]
 io_uring_create io_uring/io_uring.c:4019 [inline]
 io_uring_setup+0x13ed/0x2430 io_uring/io_uring.c:4131
 __do_sys_io_uring_setup io_uring/io_uring.c:4158 [inline]
 __se_sys_io_uring_setup io_uring/io_uring.c:4152 [inline]
 __x64_sys_io_uring_setup+0x98/0x140 io_uring/io_uring.c:4152
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f4b0e4778a9

Quoted 8 lines

Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 1a 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff814fe868 EFLAGS: 00000202 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4b0e4778a9
RDX: 0000000020000700 RSI: 0000000020000640 RDI: 0000000000005a19
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000020000700
R10: 00007fff814fe8d0 R11: 0000000000000202 R12: 0000000020000640
R13: 0000000000000000 R14: 0000000000005a19 R15: 0000000020000700
 </TASK>

Quoted 2 lines

Don't think this is io_uring related, test case looks like it's just setting up and tearing down big rings.

Can confirm it is an MM bug. Just posted the fix:
https://lore.kernel.org/[email protected]/

Yu Zhao

2023-12-23 03:30 UTC #3 lore raw

In reply to syzbot

Quoted 47 lines · syzbot

Hello,

syzbot found the following issue on:

HEAD commit:    0e389834672c Merge tag 'for-6.7-rc5-tag' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1454824ee80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f21aff374937e60e
dashboard link: https://syzkaller.appspot.com/bug?extid=03fd9b3f71641f0ebf2d
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13b4ef49e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=118314d6e80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by [email protected]

------------[ cut here ]------------
WARNING: CPU: 1 PID: 5066 at mm/vmscan.c:3242 get_pte_pfn+0x1b5/0x3f0 mm/vmscan.c:3242
Modules linked in:
CPU: 1 PID: 5066 Comm: syz-executor668 Not tainted 6.7.0-rc5-syzkaller-00270-g0e389834672c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:get_pte_pfn+0x1b5/0x3f0 mm/vmscan.c:3242
Code: f3 74 2a e8 6d 78 cb ff 31 ff 48 b8 00 00 00 00 00 00 00 02 48 21 c5 48 89 ee e8 e6 73 cb ff 48 85 ed 74 4e e8 4c 78 cb ff 90 <0f> 0b 90 48 c7 c3 ff ff ff ff e8 3c 78 cb ff 48 b8 00 00 00 00 00
RSP: 0018:ffffc900041e6878 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 000000000007891d RCX: ffffffff81bbf6e3
RDX: ffff88807d813b80 RSI: ffffffff81bbf684 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000200 R11: 0000000000000003 R12: 0000000000000200
R13: 1ffff9200083cd0f R14: 0000000000010b21 R15: 0000000020ffc000
FS:  0000555555f4d480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005fbfa000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lru_gen_look_around+0x70d/0x11a0 mm/vmscan.c:4001
 folio_referenced_one+0x5a2/0xf70 mm/rmap.c:843
 rmap_walk_anon+0x225/0x570 mm/rmap.c:2485
 rmap_walk mm/rmap.c:2562 [inline]
 rmap_walk mm/rmap.c:2557 [inline]
 folio_referenced+0x28a/0x4b0 mm/rmap.c:960
 folio_check_references mm/vmscan.c:829 [inline]
 shrink_folio_list+0x1ace/0x3f00 mm/vmscan.c:1160

Quoted 8 lines

 evict_folios+0x6e7/0x1b90 mm/vmscan.c:4499
 try_to_shrink_lruvec+0x638/0xa10 mm/vmscan.c:4704
 lru_gen_shrink_lruvec mm/vmscan.c:4849 [inline]
 shrink_lruvec+0x314/0x2990 mm/vmscan.c:5622
 shrink_node_memcgs mm/vmscan.c:5842 [inline]
 shrink_node+0x811/0x3710 mm/vmscan.c:5877
 shrink_zones mm/vmscan.c:6116 [inline]
 do_try_to_free_pages+0x36c/0x1940 mm/vmscan.c:6178

#syz test

mm/vmscan.c +11 -4

index 9dd8977de5a2..041f9ad8f95b 100644
@@ -3230,7 +3230,8 @@ static bool get_next_vma(unsigned long mask, unsigned long size, struct mm_walk
 	return false;
 }
 
-static unsigned long get_pte_pfn(pte_t pte, struct vm_area_struct *vma, unsigned long addr)
+static unsigned long get_pte_pfn(pte_t pte, struct vm_area_struct *vma, unsigned long addr,
+				 struct page *page)
 {
 	unsigned long pfn = pte_pfn(pte);

@@ -3239,8 +3240,14 @@ static unsigned long get_pte_pfn(pte_t pte, struct vm_area_struct *vma, unsigned
 	if (!pte_present(pte) || is_zero_pfn(pfn))
 		return -1;
 
-	if (WARN_ON_ONCE(pte_devmap(pte) || pte_special(pte)))
+	if (pte_devmap(pte) || pte_special(pte)) {
+		if (page)
+			dump_page(page, "get_pte_pfn()");
+		dump_vma(vma);
+		dump_mm(vma->vm_mm);
+		BUG();
 		return -1;
+	}
 
 	if (WARN_ON_ONCE(!pfn_valid(pfn)))
 		return -1;

@@ -3331,7 +3338,7 @@ static bool walk_pte_range(pmd_t *pmd, unsigned long start, unsigned long end,
 		total++;
 		walk->mm_stats[MM_LEAF_TOTAL]++;
 
-		pfn = get_pte_pfn(ptent, args->vma, addr);
+		pfn = get_pte_pfn(ptent, args->vma, addr, NULL);
 		if (pfn == -1)
 			continue;

@@ -3998,7 +4005,7 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
 		unsigned long pfn;
 		pte_t ptent = ptep_get(pte + i);
 
-		pfn = get_pte_pfn(ptent, pvmw->vma, addr);
+		pfn = get_pte_pfn(ptent, pvmw->vma, addr, pfn_to_page(pvmw->pfn));
 		if (pfn == -1)
 			continue;

syzbot

author syzbot

2023-12-23 04:02 UTC #4 lore raw

syzbot has tested the proposed patch but the reproducer is still triggering an issue: kernel BUG in get_pte_pfn

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in get_pte_pfn

ioctx_table 0000000000000000
owner ffff8880208f3b80 exe_file ffff88801a7ff180 notifier_subscriptions 0000000000000000 numa_next_scan 4294946352 numa_scan_offset 0 numa_scan_seq 0 tlb_flush_pending 0
def_flags: 0x0()

------------[ cut here ]------------
kernel BUG at mm/vmscan.c:3248!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5911 Comm: syz-executor.0 Not tainted 6.7.0-rc6-syzkaller-00248-g5254c0cbc92d-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:get_pte_pfn+0x3ec/0x450 mm/vmscan.c:3248
Code: ef e8 48 27 0a 00 49 8d 7d 10 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a 48 c1 ea 03 80 3c 02 00 75 5a 49 8b 7d 10 e8 c5 29 0a 00 90 <0f> 0b 4c 89 ef e8 fa 0f 22 00 e9 dc fc ff ff 48 c7 c7 80 43 19 8f
RSP: 0018:ffffc9000bb4e868 EFLAGS: 00010286
RAX: 0000000000000331 RBX: ffffea0001fb0240 RCX: ffffffff816a6559
RDX: 0000000000000000 RSI: ffffffff816aea02 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000200
R13: ffff88807ba95e00 R14: 1ffff92001769d0e R15: 0000000000010b22
FS:  00007ff14dc496c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000076e1e000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lru_gen_look_around+0x743/0x11f0 mm/vmscan.c:4008
 folio_referenced_one+0x5a2/0xf70 mm/rmap.c:843
 rmap_walk_anon+0x225/0x570 mm/rmap.c:2485
 rmap_walk mm/rmap.c:2562 [inline]
 rmap_walk mm/rmap.c:2557 [inline]
 folio_referenced+0x28a/0x4b0 mm/rmap.c:960
 folio_check_references mm/vmscan.c:829 [inline]
 shrink_folio_list+0x1ace/0x3f00 mm/vmscan.c:1160
 evict_folios+0x6e7/0x1b90 mm/vmscan.c:4506
 try_to_shrink_lruvec+0x638/0xa10 mm/vmscan.c:4711
 lru_gen_shrink_lruvec mm/vmscan.c:4856 [inline]
 shrink_lruvec+0x314/0x2990 mm/vmscan.c:5629
 shrink_node_memcgs mm/vmscan.c:5849 [inline]
 shrink_node+0x811/0x3710 mm/vmscan.c:5884
 shrink_zones mm/vmscan.c:6123 [inline]
 do_try_to_free_pages+0x36c/0x1940 mm/vmscan.c:6185
 try_to_free_mem_cgroup_pages+0x31a/0x770 mm/vmscan.c:6500
 try_charge_memcg+0x3d3/0x11f0 mm/memcontrol.c:2742
 obj_cgroup_charge_pages mm/memcontrol.c:3255 [inline]
 __memcg_kmem_charge_page+0xdd/0x2a0 mm/memcontrol.c:3281
 __alloc_pages+0x263/0x2420 mm/page_alloc.c:4585
 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133
 __get_free_pages+0xc/0x40 mm/page_alloc.c:4615
 io_mem_alloc+0x33/0x60 io_uring/io_uring.c:2789
 io_allocate_scq_urings io_uring/io_uring.c:3842 [inline]
 io_uring_create io_uring/io_uring.c:4019 [inline]
 io_uring_setup+0x13ed/0x2430 io_uring/io_uring.c:4131
 __do_sys_io_uring_setup io_uring/io_uring.c:4158 [inline]
 __se_sys_io_uring_setup io_uring/io_uring.c:4152 [inline]
 __x64_sys_io_uring_setup+0x98/0x140 io_uring/io_uring.c:4152
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7ff14ce7cba9
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:00007ff14dc49058 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 00007ff14cf9bf80 RCX: 00007ff14ce7cba9
RDX: 0000000020000700 RSI: 0000000020000640 RDI: 0000000000005a19
RBP: 00007ff14cec847a R08: 0000000000000000 R09: 0000000020000700
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000640
R13: 0000000000000000 R14: 0000000000005a19 R15: 0000000020000700
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:get_pte_pfn+0x3ec/0x450 mm/vmscan.c:3248
Code: ef e8 48 27 0a 00 49 8d 7d 10 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a 48 c1 ea 03 80 3c 02 00 75 5a 49 8b 7d 10 e8 c5 29 0a 00 90 <0f> 0b 4c 89 ef e8 fa 0f 22 00 e9 dc fc ff ff 48 c7 c7 80 43 19 8f
RSP: 0018:ffffc9000bb4e868 EFLAGS: 00010286
RAX: 0000000000000331 RBX: ffffea0001fb0240 RCX: ffffffff816a6559
RDX: 0000000000000000 RSI: ffffffff816aea02 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000200
R13: ffff88807ba95e00 R14: 1ffff92001769d0e R15: 0000000000010b22
FS:  00007ff14dc496c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000076e1e000 CR4: 0000000000350ef0

Tested on:

commit:         5254c0cb Merge tag 'block-6.7-2023-12-22' of git://git..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1709d481e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=314e9ad033a7d3a7
dashboard link: https://syzkaller.appspot.com/bug?extid=03fd9b3f71641f0ebf2d
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1120ad76e80000