CVE-2023-53623
mm/swap: fix swap_info_struct race between swapoff and get_swap_pages()
Description
In the Linux kernel, the following vulnerability has been resolved: mm/swap: fix swap_info_struct race between swapoff and get_swap_pages() The si->lock must be held when deleting the si from the available list. Otherwise, another thread can re-add the si to the available list, which can lead to memory corruption. The only place we have found where this happens is in the swapoff path. This case can be described as below: core 0 core 1 swapoff del_from_avail_list(si) waiting try lock si->lock acquire swap_avail_lock and re-add si into swap_avail_head acquire si->lock but missing si already being added again, and continuing to clear SWP_WRITEOK, etc. It can be easily found that a massive warning messages can be triggered inside get_swap_pages() by some special cases, for example, we call madvise(MADV_PAGEOUT) on blocks of touched memory concurrently, meanwhile, run much swapon-swapoff operations (e.g. stress-ng-swap). However, in the worst case, panic can be caused by the above scene. In swapoff(), the memory used by si could be kept in swap_info[] after turning off a swap. This means memory corruption will not be caused immediately until allocated and reset for a new swap in the swapon path. A panic message caused: (with CONFIG_PLIST_DEBUG enabled) ------------[ cut here ]------------ top: 00000000e58a3003, n: 0000000013e75cda, p: 000000008cd4451a prev: 0000000035b1e58a, n: 000000008cd4451a, p: 000000002150ee8d next: 000000008cd4451a, n: 000000008cd4451a, p: 000000008cd4451a WARNING: CPU: 21 PID: 1843 at lib/plist.c:60 plist_check_prev_next_node+0x50/0x70 Modules linked in: rfkill(E) crct10dif_ce(E)... CPU: 21 PID: 1843 Comm: stress-ng Kdump: ... 5.10.134+ Hardware name: Alibaba Cloud ECS, BIOS 0.0.0 02/06/2015 pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--) pc : plist_check_prev_next_node+0x50/0x70 lr : plist_check_prev_next_node+0x50/0x70 sp : ffff0018009d3c30 x29: ffff0018009d3c40 x28: ffff800011b32a98 x27: 0000000000000000 x26: ffff001803908000 x25: ffff8000128ea088 x24: ffff800011b32a48 x23: 0000000000000028 x22: ffff001800875c00 x21: ffff800010f9e520 x20: ffff001800875c00 x19: ffff001800fdc6e0 x18: 0000000000000030 x17: 0000000000000000 x16: 0000000000000000 x15: 0736076307640766 x14: 0730073007380731 x13: 0736076307640766 x12: 0730073007380731 x11: 000000000004058d x10: 0000000085a85b76 x9 : ffff8000101436e4 x8 : ffff800011c8ce08 x7 : 0000000000000000 x6 : 0000000000000001 x5 : ffff0017df9ed338 x4 : 0000000000000001 x3 : ffff8017ce62a000 x2 : ffff0017df9ed340 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: plist_check_prev_next_node+0x50/0x70 plist_check_head+0x80/0xf0 plist_add+0x28/0x140 add_to_avail_list+0x9c/0xf0 _enable_swap_info+0x78/0xb4 __do_sys_swapon+0x918/0xa10 __arm64_sys_swapon+0x20/0x30 el0_svc_common+0x8c/0x220 do_el0_svc+0x2c/0x90 el0_svc+0x1c/0x30 el0_sync_handler+0xa8/0xb0 el0_sync+0x148/0x180 irq event stamp: 2082270 Now, si->lock locked before calling 'del_from_avail_list()' to make sure other thread see the si had been deleted and SWP_WRITEOK cleared together, will not reinsert again. This problem exists in versions after stable 5.10.y.
INFO
Published Date :
Oct. 7, 2025, 4:15 p.m.
Last Modified :
Oct. 8, 2025, 7:38 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to a patched version.
- Ensure the lock is held before deleting from the available list.
- Verify swapoff and get_swap_pages operations are synchronized.
References to Advisories, Solutions, and Tools
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information, practical solutions, and valuable tools related to
CVE-2023-53623.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2023-53623 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2023-53623
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2023-53623 vulnerability anywhere in the article.
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CVE-2023-53623 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 07, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: mm/swap: fix swap_info_struct race between swapoff and get_swap_pages() The si->lock must be held when deleting the si from the available list. Otherwise, another thread can re-add the si to the available list, which can lead to memory corruption. The only place we have found where this happens is in the swapoff path. This case can be described as below: core 0 core 1 swapoff del_from_avail_list(si) waiting try lock si->lock acquire swap_avail_lock and re-add si into swap_avail_head acquire si->lock but missing si already being added again, and continuing to clear SWP_WRITEOK, etc. It can be easily found that a massive warning messages can be triggered inside get_swap_pages() by some special cases, for example, we call madvise(MADV_PAGEOUT) on blocks of touched memory concurrently, meanwhile, run much swapon-swapoff operations (e.g. stress-ng-swap). However, in the worst case, panic can be caused by the above scene. In swapoff(), the memory used by si could be kept in swap_info[] after turning off a swap. This means memory corruption will not be caused immediately until allocated and reset for a new swap in the swapon path. A panic message caused: (with CONFIG_PLIST_DEBUG enabled) ------------[ cut here ]------------ top: 00000000e58a3003, n: 0000000013e75cda, p: 000000008cd4451a prev: 0000000035b1e58a, n: 000000008cd4451a, p: 000000002150ee8d next: 000000008cd4451a, n: 000000008cd4451a, p: 000000008cd4451a WARNING: CPU: 21 PID: 1843 at lib/plist.c:60 plist_check_prev_next_node+0x50/0x70 Modules linked in: rfkill(E) crct10dif_ce(E)... CPU: 21 PID: 1843 Comm: stress-ng Kdump: ... 5.10.134+ Hardware name: Alibaba Cloud ECS, BIOS 0.0.0 02/06/2015 pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--) pc : plist_check_prev_next_node+0x50/0x70 lr : plist_check_prev_next_node+0x50/0x70 sp : ffff0018009d3c30 x29: ffff0018009d3c40 x28: ffff800011b32a98 x27: 0000000000000000 x26: ffff001803908000 x25: ffff8000128ea088 x24: ffff800011b32a48 x23: 0000000000000028 x22: ffff001800875c00 x21: ffff800010f9e520 x20: ffff001800875c00 x19: ffff001800fdc6e0 x18: 0000000000000030 x17: 0000000000000000 x16: 0000000000000000 x15: 0736076307640766 x14: 0730073007380731 x13: 0736076307640766 x12: 0730073007380731 x11: 000000000004058d x10: 0000000085a85b76 x9 : ffff8000101436e4 x8 : ffff800011c8ce08 x7 : 0000000000000000 x6 : 0000000000000001 x5 : ffff0017df9ed338 x4 : 0000000000000001 x3 : ffff8017ce62a000 x2 : ffff0017df9ed340 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: plist_check_prev_next_node+0x50/0x70 plist_check_head+0x80/0xf0 plist_add+0x28/0x140 add_to_avail_list+0x9c/0xf0 _enable_swap_info+0x78/0xb4 __do_sys_swapon+0x918/0xa10 __arm64_sys_swapon+0x20/0x30 el0_svc_common+0x8c/0x220 do_el0_svc+0x2c/0x90 el0_svc+0x1c/0x30 el0_sync_handler+0xa8/0xb0 el0_sync+0x148/0x180 irq event stamp: 2082270 Now, si->lock locked before calling 'del_from_avail_list()' to make sure other thread see the si had been deleted and SWP_WRITEOK cleared together, will not reinsert again. This problem exists in versions after stable 5.10.y. Added Reference https://git.kernel.org/stable/c/111a79d9b92f0a679fe300ccd3119ae9741f3d54 Added Reference https://git.kernel.org/stable/c/4bdf1514b4268d29360ba9e43becdd49955bc7ae Added Reference https://git.kernel.org/stable/c/6fe7d6b992113719e96744d974212df3fcddc76c Added Reference https://git.kernel.org/stable/c/85cc118ce6f1a627901b6db50c9d01f2ad78cdbf Added Reference https://git.kernel.org/stable/c/a55f268abdb74ac5633b75a09fefb58458e9d2a2 Added Reference https://git.kernel.org/stable/c/b9927d3a60ca9ed35625470888629c074e687ba0 Added Reference https://git.kernel.org/stable/c/e7bba7ddb4318d5ea939c8db747c2c2780ab66f4 Added Reference https://git.kernel.org/stable/c/ea8c42b3b6d95ced3a4f555f04686d00ef0bb206