{"id":"CVE-2024-26957","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/zcrypt: fix reference counting on zcrypt card objects\n\nTests with hot-plugging crytpo cards on KVM guests with debug\nkernel build revealed an use after free for th…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/zcrypt: fix reference counting on zcrypt card objects\n\nTests with hot-plugging crytpo cards on KVM guests with debug\nkernel build revealed an use after free for th…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel < 4.19.312","linux_kernel >= 4.20, < 5.4.274","linux_kernel >= 5.5, < 5.10.215","linux_kernel >= 5.11, < 5.15.154","linux_kernel >= 5.16, < 6.1.84","linux_kernel >= 6.2, < 6.6.24","linux_kernel >= 6.7, < 6.7.12","linux_kernel >= 6.8, < 6.8.3","debian_linux = 10.0"],"patched":["linux_kernel 6.8.3"],"published":"2024-05-01","updated":"2026-10-15","sourceUpdated":"2026-10-15T01:17:33.657","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2024-26957","references":[{"url":"https://git.kernel.org/stable/c/394b6d8bbdf9ddee6d5bcf3e1f3e9f23eecd6484","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/50ed48c80fecbe17218afed4f8bed005c802976c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6470078ab3d8f222115e11c4ec67351f3031b3dd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7e500849fa558879a1cde43f80c7c048c2437058","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9daddee03de3f231012014dab8ab2b277a116a55","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a55677878b93e9ebc31f66d0e2fb93be5e7836a6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a64ab862e84e3e698cd351a87cdb504c7fc575ca","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b7f6c3630eb3f103115ab0d7613588064f665d0d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/befb7f889594d23e1b475720cf93efd2f77df000","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/394b6d8bbdf9ddee6d5bcf3e1f3e9f23eecd6484","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/50ed48c80fecbe17218afed4f8bed005c802976c","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/6470078ab3d8f222115e11c4ec67351f3031b3dd","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/7e500849fa558879a1cde43f80c7c048c2437058","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/9daddee03de3f231012014dab8ab2b277a116a55","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a55677878b93e9ebc31f66d0e2fb93be5e7836a6","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a64ab862e84e3e698cd351a87cdb504c7fc575ca","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/b7f6c3630eb3f103115ab0d7613588064f665d0d","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/befb7f889594d23e1b475720cf93efd2f77df000","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00241,"epssPercentile":0.15119,"ingestedAt":"2026-10-15T03:30:12.664Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2024-06-17T15:58:32.988246Z"},"slug":"CVE-2024-26957","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ns390/zcrypt: fix reference counting on zcrypt card objects\n\nTests with hot-plugging crytpo cards on KVM guests with debug\nkernel build revealed an use after free for the load field of\nthe struct zcrypt_card. The reason was an incorrect reference\nhandling of the zcrypt card object which could lead to a free\nof the zcrypt card object while it was still in use.\n\nThis is an example of the slab message:\n\n    kernel: 0x00000000885a7512-0x00000000885a7513 @offset=1298. First byte 0x68 instead of 0x6b\n    kernel: Allocated in zcrypt_card_alloc+0x36/0x70 [zcrypt] age=18046 cpu=3 pid=43\n    kernel:  kmalloc_trace+0x3f2/0x470\n    kernel:  zcrypt_card_alloc+0x36/0x70 [zcrypt]\n    kernel:  zcrypt_cex4_card_probe+0x26/0x380 [zcrypt_cex4]\n    kernel:  ap_device_probe+0x15c/0x290\n    kernel:  really_probe+0xd2/0x468\n    kernel:  driver_probe_device+0x40/0xf0\n    kernel:  __device_attach_driver+0xc0/0x140\n    kernel:  bus_for_each_drv+0x8c/0xd0\n    kernel:  __device_attach+0x114/0x198\n    kernel:  bus_probe_device+0xb4/0xc8\n    kernel:  device_add+0x4d2/0x6e0\n    kernel:  ap_scan_adapter+0x3d0/0x7c0\n    kernel:  ap_scan_bus+0x5a/0x3b0\n    kernel:  ap_scan_bus_wq_callback+0x40/0x60\n    kernel:  process_one_work+0x26e/0x620\n    kernel:  worker_thread+0x21c/0x440\n    kernel: Freed in zcrypt_card_put+0x54/0x80 [zcrypt] age=9024 cpu=3 pid=43\n    kernel:  kfree+0x37e/0x418\n    kernel:  zcrypt_card_put+0x54/0x80 [zcrypt]\n    kernel:  ap_device_remove+0x4c/0xe0\n    kernel:  device_release_driver_internal+0x1c4/0x270\n    kernel:  bus_remove_device+0x100/0x188\n    kernel:  device_del+0x164/0x3c0\n    kernel:  device_unregister+0x30/0x90\n    kernel:  ap_scan_adapter+0xc8/0x7c0\n    kernel:  ap_scan_bus+0x5a/0x3b0\n    kernel:  ap_scan_bus_wq_callback+0x40/0x60\n    kernel:  process_one_work+0x26e/0x620\n    kernel:  worker_thread+0x21c/0x440\n    kernel:  kthread+0x150/0x168\n    kernel:  __ret_from_fork+0x3c/0x58\n    kernel:  ret_from_fork+0xa/0x30\n    kernel: Slab 0x00000372022169c0 objects=20 used=18 fp=0x00000000885a7c88 flags=0x3ffff00000000a00(workingset|slab|node=0|zone=1|lastcpupid=0x1ffff)\n    kernel: Object 0x00000000885a74b8 @offset=1208 fp=0x00000000885a7c88\n    kernel: Redzone  00000000885a74b0: bb bb bb bb bb bb bb bb                          ........\n    kernel: Object   00000000885a74b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk\n    kernel: Object   00000000885a74c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk\n    kernel: Object   00000000885a74d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk\n    kernel: Object   00000000885a74e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk\n    kernel: Object   00000000885a74f8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk\n    kernel: Object   00000000885a7508: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 68 4b 6b 6b 6b a5  kkkkkkkkkkhKkkk.\n    kernel: Redzone  00000000885a7518: bb bb bb bb bb bb bb bb                          ........\n    kernel: Padding  00000000885a756c: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a              ZZZZZZZZZZZZ\n    kernel: CPU: 0 PID: 387 Comm: systemd-udevd Not tainted 6.8.0-HF #2\n    kernel: Hardware name: IBM 3931 A01 704 (KVM/Linux)\n    kernel: Call Trace:\n    kernel:  [<00000000ca5ab5b8>] dump_stack_lvl+0x90/0x120\n    kernel:  [<00000000c99d78bc>] check_bytes_and_report+0x114/0x140\n    kernel:  [<00000000c99d53cc>] check_object+0x334/0x3f8\n    kernel:  [<00000000c99d820c>] alloc_debug_processing+0xc4/0x1f8\n    kernel:  [<00000000c99d852e>] get_partial_node.part.0+0x1ee/0x3e0\n    kernel:  [<00000000c99d94ec>] ___slab_alloc+0xaf4/0x13c8\n    kernel:  [<00000000c99d9e38>] __slab_alloc.constprop.0+0x78/0xb8\n    kernel:  [<00000000c99dc8dc>] __kmalloc+0x434/0x590\n    kernel:  [<00000000c9b4c0ce>] ext4_htree_store_dirent+0x4e/0x1c0\n    kernel:  [<00000000c9b908a2>] htree_dirblock_to_tree+0x17a/0x3f0\n    kernel: \n---truncated---\n\n## Affected\n\n- `linux_kernel < 4.19.312`\n- `linux_kernel >= 4.20, < 5.4.274`\n- `linux_kernel >= 5.5, < 5.10.215`\n- `linux_kernel >= 5.11, < 5.15.154`\n- `linux_kernel >= 5.16, < 6.1.84`\n- `linux_kernel >= 6.2, < 6.6.24`\n- `linux_kernel >= 6.7, < 6.7.12`\n- `linux_kernel >= 6.8, < 6.8.3`\n- `debian_linux = 10.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.8.3`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}