UBUNTU-CVE-2024-57884
In the Linux kernel, the following vulnerability has been resolved: mm: vmscan: account for free pages to prevent infinite Loop in throttle_direct_reclaim() The task sometimes continues looping in throttle_direct_reclaim() because allow_direct_reclaim(pgdat) keeps returning false. #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c #2 [ffff80002cb6f990] schedule at ffff800008abc50c #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4 At this point, the pgdat contains the following two zones: NODE: 4 ZONE: 0 ADDR: ffff00817fffe540 NAME: "DMA32" SIZE: 20480 MIN/LOW/HIGH: 11/28/45 VM_STAT: NR_FREE_PAGES: 359 NR_ZONE_INACTIVE_ANON: 18813 NR_ZONE_ACTIVE_ANON: 0 NR_ZONE_INACTIVE_FILE: 50 NR_ZONE_ACTIVE_FILE: 0 NR_ZONE_UNEVICTABLE: 0 NR_ZONE_WRITE_PENDING: 0 NR_MLOCK: 0 NR_BOUNCE: 0 NR_ZSPAGES: 0 NR_FREE_CMA_PAGES: 0 NODE: 4 ZONE: 1 ADDR: ffff00817fffec00 NAME: "Normal" SIZE: 8454144 PRESENT: 98304 MIN/LOW/HIGH: 68/166/264 VM_STAT: NR_FREE_PAGES: 146 NR_ZONE_INACTIVE_ANON: 94668 NR_ZONE_ACTIVE_ANON: 3 NR_ZONE_INACTIVE_FILE: 735 NR_ZONE_ACTIVE_FILE: 78 NR_ZONE_UNEVICTABLE: 0 NR_ZONE_WRITE_PENDING: 0 NR_MLOCK: 0 NR_BOUNCE: 0 NR_ZSPAGES: 0 NR_FREE_CMA_PAGES: 0 In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of inactive/active file-backed pages calculated in zone_reclaimable_pages() based on the result of zone_page_state_snapshot() is zero. Additionally, since this system lacks swap, the calculation of inactive/ active anonymous pages is skipped. crash> p nr_swap_pages nr_swap_pages = $1937 = { counter = 0 } As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having free pages significantly exceeding the high watermark. The problem is that the pgdat->kswapd_failures hasn't been incremented. crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures $1935 = 0x0 This is because the node deemed balanced. The node balancing logic in balance_pgdat() evaluates all zones collectively. If one or more zones (e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the entire node is deemed balanced. This causes balance_pgdat() to exit early before incrementing the kswapd_failures, as it considers the overall memory state acceptable, even though some zones (like ZONE_NORMAL) remain under significant pressure. The patch ensures that zone_reclaimable_pages() includes free pages (NR_FREE_PAGES) in its calculation when no other reclaimable pages are available (e.g., file-backed or anonymous pages). This change prevents zones like ZONE_DMA32, which have sufficient free pages, from being mistakenly deemed unreclaimable. By doing so, the patch ensures proper node balancing, avoids masking pressure on other zones like ZONE_NORMAL, and prevents infinite loops in throttle_direct_reclaim() caused by allow_direct_reclaim(pgdat) repeatedly returning false. The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused by a node being incorrectly deemed balanced despite pressure in certain zones, such as ZONE_NORMAL. This issue arises from zone_reclaimable_pages ---truncated---
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
43 explicit affected versions
59 explicit affected versions
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
19 explicit affected versions
6 explicit affected versions
69 explicit affected versions
23 explicit affected versions
54 explicit affected versions
72 explicit affected versions
62 explicit affected versions
55 explicit affected versions
10 explicit affected versions
14 explicit affected versions
21 explicit affected versions
61 explicit affected versions
7 explicit affected versions
60 explicit affected versions
18 explicit affected versions
100 explicit affected versions
13 explicit affected versions
85 explicit affected versions
20 explicit affected versions
35 explicit affected versions
21 explicit affected versions
19 explicit affected versions
18 explicit affected versions
20 explicit affected versions
118 explicit affected versions
64 explicit affected versions
23 explicit affected versions
102 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
28 explicit affected versions
1 explicit affected versions
1 explicit affected versions
21 explicit affected versions
16 explicit affected versions
10 explicit affected versions
57 explicit affected versions
24 explicit affected versions
2 explicit affected versions
7 explicit affected versions
12 explicit affected versions
111 explicit affected versions
1 explicit affected versions
52 explicit affected versions
12 explicit affected versions
14 explicit affected versions
7 explicit affected versions
2 explicit affected versions
89 explicit affected versions
12 explicit affected versions
105 explicit affected versions
113 explicit affected versions
12 explicit affected versions
18 explicit affected versions
100 explicit affected versions
15 explicit affected versions
15 explicit affected versions
10 explicit affected versions
10 explicit affected versions
37 explicit affected versions
2 explicit affected versions
13 explicit affected versions
16 explicit affected versions
10 explicit affected versions
1 explicit affected versions
37 explicit affected versions
26 explicit affected versions
13 explicit affected versions
12 explicit affected versions
1 explicit affected versions
29 explicit affected versions
93 explicit affected versions
13 explicit affected versions
66 explicit affected versions
17 explicit affected versions
18 explicit affected versions
1 explicit affected versions
87 explicit affected versions
61 explicit affected versions
105 explicit affected versions
24 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
1 explicit affected versions
11 explicit affected versions
12 explicit affected versions
7 explicit affected versions
12 explicit affected versions
103 explicit affected versions
138 explicit affected versions
52 explicit affected versions
46 explicit affected versions
132 explicit affected versions
62 explicit affected versions
154 explicit affected versions
10 explicit affected versions
26 explicit affected versions
22 explicit affected versions
38 explicit affected versions
1 explicit affected versions
13 explicit affected versions
23 explicit affected versions
13 explicit affected versions
23 explicit affected versions
139 explicit affected versions
63 explicit affected versions
16 explicit affected versions
63 explicit affected versions
26 explicit affected versions
53 explicit affected versions
116 explicit affected versions
3 explicit affected versions
93 explicit affected versions
1 explicit affected versions
1 explicit affected versions
2 explicit affected versions
70 explicit affected versions
51 explicit affected versions
92 explicit affected versions
9 explicit affected versions
20 explicit affected versions
12 explicit affected versions
49 explicit affected versions
27 explicit affected versions
36 explicit affected versions
1 explicit affected versions
1 explicit affected versions
98 explicit affected versions
19 explicit affected versions
8 explicit affected versions
26 explicit affected versions
5 explicit affected versions
8 explicit affected versions
1 explicit affected versions
10 explicit affected versions
22 explicit affected versions
13 explicit affected versions
92 explicit affected versions
13 explicit affected versions
56 explicit affected versions
7 explicit affected versions
140 explicit affected versions
2 explicit affected versions
94 explicit affected versions
54 explicit affected versions
10 explicit affected versions
12 explicit affected versions
15 explicit affected versions
91 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
27 explicit affected versions
14 explicit affected versions
38 explicit affected versions
167 explicit affected versions
53 explicit affected versions
9 explicit affected versions
51 explicit affected versions
11 explicit affected versions
17 explicit affected versions
7 explicit affected versions
62 explicit affected versions
7 explicit affected versions
33 explicit affected versions
64 explicit affected versions
121 explicit affected versions
4 explicit affected versions
1 explicit affected versions
1 explicit affected versions
1 explicit affected versions
60 explicit affected versions
13 explicit affected versions
43 explicit affected versions
58 explicit affected versions
10 explicit affected versions
8 explicit affected versions
21 explicit affected versions
14 explicit affected versions
92 explicit affected versions
4 explicit affected versions
78 explicit affected versions
11 explicit affected versions
1 explicit affected versions
69 explicit affected versions
16 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: mm: vmscan: account for free pages to prevent infinite Loop in throttle_direct_reclaim() The task sometimes continues looping in throttle_direct_reclaim() because allow_direct_reclaim(pgdat) keeps returning false. #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c #2 [ffff80002cb6f990] schedule at ffff800008abc50c #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4 At this point, the pgdat contains the following two zones: NODE: 4 ZONE: 0 ADDR: ffff00817fffe540 NAME: "DMA32" SIZE: 20480 MIN/LOW/HIGH: 11/28/45 VM_STAT: NR_FREE_PAGES: 359 NR_ZONE_INACTIVE_ANON: 18813 NR_ZONE_ACTIVE_ANON: 0 NR_ZONE_INACTIVE_FILE: 50 NR_ZONE_ACTIVE_FILE: 0 NR_ZONE_UNEVICTABLE: 0 NR_ZONE_WRITE_PENDING: 0 NR_MLOCK: 0 NR_BOUNCE: 0 NR_ZSPAGES: 0 NR_FREE_CMA_PAGES: 0 NODE: 4 ZONE: 1 ADDR: ffff00817fffec00 NAME: "Normal" SIZE: 8454144 PRESENT: 98304 MIN/LOW/HIGH: 68/166/264 VM_STAT: NR_FREE_PAGES: 146 NR_ZONE_INACTIVE_ANON: 94668 NR_ZONE_ACTIVE_ANON: 3 NR_ZONE_INACTIVE_FILE: 735 NR_ZONE_ACTIVE_FILE: 78 NR_ZONE_UNEVICTABLE: 0 NR_ZONE_WRITE_PENDING: 0 NR_MLOCK: 0 NR_BOUNCE: 0 NR_ZSPAGES: 0 NR_FREE_CMA_PAGES: 0 In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of inactive/active file-backed pages calculated in zone_reclaimable_pages() based on the result of zone_page_state_snapshot() is zero. Additionally, since this system lacks swap, the calculation of inactive/ active anonymous pages is skipped. crash> p nr_swap_pages nr_swap_pages = $1937 = { counter = 0 } As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having free pages significantly exceeding the high watermark. The problem is that the pgdat->kswapd_failures hasn't been incremented. crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures $1935 = 0x0 This is because the node deemed balanced. The node balancing logic in balance_pgdat() evaluates all zones collectively. If one or more zones (e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the entire node is deemed balanced. This causes balance_pgdat() to exit early before incrementing the kswapd_failures, as it considers the overall memory state acceptable, even though some zones (like ZONE_NORMAL) remain under significant pressure. The patch ensures that zone_reclaimable_pages() includes free pages (NR_FREE_PAGES) in its calculation when no other reclaimable pages are available (e.g., file-backed or anonymous pages). This change prevents zones like ZONE_DMA32, which have sufficient free pages, from being mistakenly deemed unreclaimable. By doing so, the patch ensures proper node balancing, avoids masking pressure on other zones like ZONE_NORMAL, and prevents infinite loops in throttle_direct_reclaim() caused by allow_direct_reclaim(pgdat) repeatedly returning false. The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused by a node being incorrectly deemed balanced despite pressure in certain zones, such as ZONE_NORMAL. This issue arises from zone_reclaimable_pages ---truncated---
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/6aaced5abd32e2a57cd94fd64f824514d0361da8
- https://git.kernel.org/stable/c/1ff2302e8aeac7f2eedb551d7a89617283b5c6b2
- https://git.kernel.org/stable/c/58d0d02dbc67438fc80223fdd7bbc49cf0733284
- https://git.kernel.org/stable/c/63eac98d6f0898229f515cb62fe4e4db2430e99c
- https://git.kernel.org/stable/c/66cd37660ec34ec444fe42f2277330ae4a36bb19
- https://git.kernel.org/stable/c/6aaced5abd32e2a57cd94fd64f824514d0361da8
- https://git.kernel.org/stable/c/bfb701192129803191c9cd6cdd1f82cd07f8de2c
- https://git.kernel.org/stable/c/d675fefbaec3815b3ae0af1bebd97f27df3a05c8
- https://ubuntu.com/security/CVE-2024-57884
- https://ubuntu.com/security/notices/USN-7379-1
- https://ubuntu.com/security/notices/USN-7379-2
- https://ubuntu.com/security/notices/USN-7380-1
- https://ubuntu.com/security/notices/USN-7381-1
- https://ubuntu.com/security/notices/USN-7382-1
- https://ubuntu.com/security/notices/USN-7387-1
- https://ubuntu.com/security/notices/USN-7387-2
- https://ubuntu.com/security/notices/USN-7387-3
- https://ubuntu.com/security/notices/USN-7388-1
- https://ubuntu.com/security/notices/USN-7389-1
- https://ubuntu.com/security/notices/USN-7390-1
- https://ubuntu.com/security/notices/USN-7391-1
- https://ubuntu.com/security/notices/USN-7392-1
- https://ubuntu.com/security/notices/USN-7392-2
- https://ubuntu.com/security/notices/USN-7392-3
- https://ubuntu.com/security/notices/USN-7392-4
- https://ubuntu.com/security/notices/USN-7393-1
- https://ubuntu.com/security/notices/USN-7401-1
- https://ubuntu.com/security/notices/USN-7407-1
- https://ubuntu.com/security/notices/USN-7413-1
- https://ubuntu.com/security/notices/USN-7421-1
- https://ubuntu.com/security/notices/USN-7458-1
- https://ubuntu.com/security/notices/USN-7459-1
- https://ubuntu.com/security/notices/USN-7459-2
- https://ubuntu.com/security/notices/USN-7463-1
- https://ubuntu.com/security/notices/USN-7513-1
- https://ubuntu.com/security/notices/USN-7513-2
- https://ubuntu.com/security/notices/USN-7513-3
- https://ubuntu.com/security/notices/USN-7513-4
- https://ubuntu.com/security/notices/USN-7513-5
- https://ubuntu.com/security/notices/USN-7514-1
- https://ubuntu.com/security/notices/USN-7515-1
- https://ubuntu.com/security/notices/USN-7515-2
- https://ubuntu.com/security/notices/USN-7522-1
- https://ubuntu.com/security/notices/USN-7523-1
- https://ubuntu.com/security/notices/USN-7524-1
- https://ubuntu.com/security/notices/USN-7539-1
- https://ubuntu.com/security/notices/USN-7540-1
- https://www.cve.org/CVERecord?id=CVE-2024-57884