UBUNTU-CVE-2025-37834
In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: don't try to reclaim hwpoison folio Syzkaller reports a bug as follows: Injecting memory failure for pfn 0x18b00e at process virtual address 0x20ffd000 Memory failure: 0x18b00e: dirty swapcache page still referenced by 2 users Memory failure: 0x18b00e: recovery action for dirty swapcache page: Failed page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x20ffd pfn:0x18b00e memcg:ffff0000dd6d9000 anon flags: 0x5ffffe00482011(locked|dirty|arch_1|swapbacked|hwpoison|node=0|zone=2|lastcpupid=0xfffff) raw: 005ffffe00482011 dead000000000100 dead000000000122 ffff0000e232a7c9 raw: 0000000000020ffd 0000000000000000 00000002ffffffff ffff0000dd6d9000 page dumped because: VM_BUG_ON_FOLIO(!folio_test_uptodate(folio)) ------------[ cut here ]------------ kernel BUG at mm/swap_state.c:184! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Modules linked in: CPU: 0 PID: 60 Comm: kswapd0 Not tainted 6.6.0-gcb097e7de84e #3 Hardware name: linux,dummy-virt (DT) pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : add_to_swap+0xbc/0x158 lr : add_to_swap+0xbc/0x158 sp : ffff800087f37340 x29: ffff800087f37340 x28: fffffc00052c0380 x27: ffff800087f37780 x26: ffff800087f37490 x25: ffff800087f37c78 x24: ffff800087f377a0 x23: ffff800087f37c50 x22: 0000000000000000 x21: fffffc00052c03b4 x20: 0000000000000000 x19: fffffc00052c0380 x18: 0000000000000000 x17: 296f696c6f662865 x16: 7461646f7470755f x15: 747365745f6f696c x14: 6f6621284f494c4f x13: 0000000000000001 x12: ffff600036d8b97b x11: 1fffe00036d8b97a x10: ffff600036d8b97a x9 : dfff800000000000 x8 : 00009fffc9274686 x7 : ffff0001b6c5cbd3 x6 : 0000000000000001 x5 : ffff0000c25896c0 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : ffff0000c25896c0 x0 : 0000000000000000 Call trace: add_to_swap+0xbc/0x158 shrink_folio_list+0x12ac/0x2648 shrink_inactive_list+0x318/0x948 shrink_lruvec+0x450/0x720 shrink_node_memcgs+0x280/0x4a8 shrink_node+0x128/0x978 balance_pgdat+0x4f0/0xb20 kswapd+0x228/0x438 kthread+0x214/0x230 ret_from_fork+0x10/0x20 I can reproduce this issue with the following steps: 1) When a dirty swapcache page is isolated by reclaim process and the page isn't locked, inject memory failure for the page. me_swapcache_dirty() clears uptodate flag and tries to delete from lru, but fails. Reclaim process will put the hwpoisoned page back to lru. 2) The process that maps the hwpoisoned page exits, the page is deleted the page will never be freed and will be in the lru forever. 3) If we trigger a reclaim again and tries to reclaim the page, add_to_swap() will trigger VM_BUG_ON_FOLIO due to the uptodate flag is cleared. To fix it, skip the hwpoisoned page in shrink_folio_list(). Besides, the hwpoison folio may not be unmapped by hwpoison_user_mappings() yet, unmap it in shrink_folio_list(), otherwise the folio will fail to be unmaped by hwpoison_user_mappings() since the folio isn't in lru list.
02 / AFFECTED SOFTWARE
Affected packages
132 explicit affected versions
71 explicit affected versions
80 explicit affected versions
86 explicit affected versions
11 explicit affected versions
13 explicit affected versions
53 explicit affected versions
116 explicit affected versions
89 explicit affected versions
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
19 explicit affected versions
6 explicit affected versions
100 explicit affected versions
61 explicit affected versions
24 explicit affected versions
85 explicit affected versions
84 explicit affected versions
91 explicit affected versions
167 explicit affected versions
76 explicit affected versions
10 explicit affected versions
39 explicit affected versions
26 explicit affected versions
77 explicit affected versions
90 explicit affected versions
191 explicit affected versions
7 explicit affected versions
84 explicit affected versions
111 explicit affected versions
42 explicit affected versions
13 explicit affected versions
85 explicit affected versions
46 explicit affected versions
42 explicit affected versions
35 explicit affected versions
51 explicit affected versions
50 explicit affected versions
18 explicit affected versions
118 explicit affected versions
64 explicit affected versions
48 explicit affected versions
120 explicit affected versions
8 explicit affected versions
13 explicit affected versions
4 explicit affected versions
121 explicit affected versions
23 explicit affected versions
7 explicit affected versions
55 explicit affected versions
124 explicit affected versions
1 explicit affected versions
1 explicit affected versions
21 explicit affected versions
12 explicit affected versions
9 explicit affected versions
16 explicit affected versions
10 explicit affected versions
76 explicit affected versions
51 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
10 explicit affected versions
1 explicit affected versions
1 explicit affected versions
7 explicit affected versions
19 explicit affected versions
104 explicit affected versions
12 explicit affected versions
105 explicit affected versions
12 explicit affected versions
44 explicit affected versions
120 explicit affected versions
92 explicit affected versions
45 explicit affected versions
29 explicit affected versions
37 explicit affected versions
10 explicit affected versions
37 explicit affected versions
10 explicit affected versions
13 explicit affected versions
42 explicit affected versions
10 explicit affected versions
1 explicit affected versions
68 explicit affected versions
26 explicit affected versions
12 explicit affected versions
13 explicit affected versions
144 explicit affected versions
37 explicit affected versions
1 explicit affected versions
29 explicit affected versions
111 explicit affected versions
13 explicit affected versions
96 explicit affected versions
43 explicit affected versions
43 explicit affected versions
1 explicit affected versions
100 explicit affected versions
55 explicit affected versions
33 explicit affected versions
23 explicit affected versions
60 explicit affected versions
10 explicit affected versions
23 explicit affected versions
188 explicit affected versions
22 explicit affected versions
11 explicit affected versions
12 explicit affected versions
7 explicit affected versions
12 explicit affected versions
138 explicit affected versions
2 explicit affected versions
132 explicit affected versions
93 explicit affected versions
165 explicit affected versions
154 explicit affected versions
10 explicit affected versions
26 explicit affected versions
42 explicit affected versions
1 explicit affected versions
69 explicit affected versions
37 explicit affected versions
78 explicit affected versions
48 explicit affected versions
13 explicit affected versions
48 explicit affected versions
139 explicit affected versions
16 explicit affected versions
91 explicit affected versions
53 explicit affected versions
116 explicit affected versions
3 explicit affected versions
93 explicit affected versions
1 explicit affected versions
7 explicit affected versions
2 explicit affected versions
51 explicit affected versions
92 explicit affected versions
18 explicit affected versions
43 explicit affected versions
12 explicit affected versions
27 explicit affected versions
66 explicit affected versions
121 explicit affected versions
1 explicit affected versions
1 explicit affected versions
98 explicit affected versions
45 explicit affected versions
8 explicit affected versions
55 explicit affected versions
5 explicit affected versions
110 explicit affected versions
3 explicit affected versions
8 explicit affected versions
1 explicit affected versions
10 explicit affected versions
7 explicit affected versions
49 explicit affected versions
13 explicit affected versions
72 explicit affected versions
7 explicit affected versions
140 explicit affected versions
8 explicit affected versions
94 explicit affected versions
10 explicit affected versions
12 explicit affected versions
1 explicit affected versions
39 explicit affected versions
108 explicit affected versions
80 explicit affected versions
56 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
53 explicit affected versions
14 explicit affected versions
38 explicit affected versions
80 explicit affected versions
9 explicit affected versions
11 explicit affected versions
42 explicit affected versions
21 explicit affected versions
92 explicit affected versions
79 explicit affected versions
8 explicit affected versions
7 explicit affected versions
97 explicit affected versions
121 explicit affected versions
4 explicit affected versions
13 explicit affected versions
81 explicit affected versions
1 explicit affected versions
1 explicit affected versions
1 explicit affected versions
91 explicit affected versions
43 explicit affected versions
77 explicit affected versions
119 explicit affected versions
5 explicit affected versions
10 explicit affected versions
8 explicit affected versions
48 explicit affected versions
88 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
11 explicit affected versions
1 explicit affected versions
69 explicit affected versions
123 explicit affected versions
22 explicit affected versions
41 explicit affected versions
80 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: don't try to reclaim hwpoison folio Syzkaller reports a bug as follows: Injecting memory failure for pfn 0x18b00e at process virtual address 0x20ffd000 Memory failure: 0x18b00e: dirty swapcache page still referenced by 2 users Memory failure: 0x18b00e: recovery action for dirty swapcache page: Failed page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x20ffd pfn:0x18b00e memcg:ffff0000dd6d9000 anon flags: 0x5ffffe00482011(locked|dirty|arch_1|swapbacked|hwpoison|node=0|zone=2|lastcpupid=0xfffff) raw: 005ffffe00482011 dead000000000100 dead000000000122 ffff0000e232a7c9 raw: 0000000000020ffd 0000000000000000 00000002ffffffff ffff0000dd6d9000 page dumped because: VM_BUG_ON_FOLIO(!folio_test_uptodate(folio)) ------------[ cut here ]------------ kernel BUG at mm/swap_state.c:184! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Modules linked in: CPU: 0 PID: 60 Comm: kswapd0 Not tainted 6.6.0-gcb097e7de84e #3 Hardware name: linux,dummy-virt (DT) pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : add_to_swap+0xbc/0x158 lr : add_to_swap+0xbc/0x158 sp : ffff800087f37340 x29: ffff800087f37340 x28: fffffc00052c0380 x27: ffff800087f37780 x26: ffff800087f37490 x25: ffff800087f37c78 x24: ffff800087f377a0 x23: ffff800087f37c50 x22: 0000000000000000 x21: fffffc00052c03b4 x20: 0000000000000000 x19: fffffc00052c0380 x18: 0000000000000000 x17: 296f696c6f662865 x16: 7461646f7470755f x15: 747365745f6f696c x14: 6f6621284f494c4f x13: 0000000000000001 x12: ffff600036d8b97b x11: 1fffe00036d8b97a x10: ffff600036d8b97a x9 : dfff800000000000 x8 : 00009fffc9274686 x7 : ffff0001b6c5cbd3 x6 : 0000000000000001 x5 : ffff0000c25896c0 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : ffff0000c25896c0 x0 : 0000000000000000 Call trace: add_to_swap+0xbc/0x158 shrink_folio_list+0x12ac/0x2648 shrink_inactive_list+0x318/0x948 shrink_lruvec+0x450/0x720 shrink_node_memcgs+0x280/0x4a8 shrink_node+0x128/0x978 balance_pgdat+0x4f0/0xb20 kswapd+0x228/0x438 kthread+0x214/0x230 ret_from_fork+0x10/0x20 I can reproduce this issue with the following steps: 1) When a dirty swapcache page is isolated by reclaim process and the page isn't locked, inject memory failure for the page. me_swapcache_dirty() clears uptodate flag and tries to delete from lru, but fails. Reclaim process will put the hwpoisoned page back to lru. 2) The process that maps the hwpoisoned page exits, the page is deleted the page will never be freed and will be in the lru forever. 3) If we trigger a reclaim again and tries to reclaim the page, add_to_swap() will trigger VM_BUG_ON_FOLIO due to the uptodate flag is cleared. To fix it, skip the hwpoisoned page in shrink_folio_list(). Besides, the hwpoison folio may not be unmapped by hwpoison_user_mappings() yet, unmap it in shrink_folio_list(), otherwise the folio will fail to be unmaped by hwpoison_user_mappings() since the folio isn't in lru list.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/1b0449544c6482179ac84530b61fc192a6527bfd
- https://ubuntu.com/security/CVE-2025-37834
- https://ubuntu.com/security/notices/USN-7594-1
- https://ubuntu.com/security/notices/USN-7594-2
- https://ubuntu.com/security/notices/USN-7594-3
- https://www.cve.org/CVERecord?id=CVE-2025-37834