{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2024-44946", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2024-44946", "idYear": 2024, "status": "PUBLISHED", "publishedAt": "2024-08-31T13:22:47.250Z", "updatedAt": "2026-08-05T11:37:13.816Z", "importedAt": "2026-10-24T01:57:16.009Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "kcm: Serialise kcm_sendmsg() for the same socket.", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nkcm: Serialise kcm_sendmsg() for the same socket.\n\nsyzkaller reported UAF in kcm_release(). [0]\n\nThe scenario is\n\n 1. Thread A builds a skb with MSG_MORE and sets kcm->seq_skb.\n\n 2. Thread A resumes building skb from kcm->seq_skb but is blocked\n by sk_stream_wait_memory()\n\n 3. Thread B calls sendmsg() concurrently, finishes building kcm->seq_skb\n and puts the skb to the write queue\n\n 4. Thread A faces an error and finally frees skb that is already in the\n write queue\n\n 5. kcm_release() does double-free the skb in the write queue\n\nWhen a thread is building a MSG_MORE skb, another thread must not touch it.\n\nLet's add a per-sk mutex and serialise kcm_sendmsg().\n\n[0]:\nBUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline]\nBUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline]\nBUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]\nBUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline]\nBUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691\nRead of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167\n\nCPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G B 6.8.0-rc5-syzkaller-g9abbc24128bc #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024\nCall trace:\n dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291\n show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0x178/0x518 mm/kasan/report.c:488\n kasan_report+0xd8/0x138 mm/kasan/report.c:601\n __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381\n __skb_unlink include/linux/skbuff.h:2366 [inline]\n __skb_dequeue include/linux/skbuff.h:2385 [inline]\n __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]\n __skb_queue_purge include/linux/skbuff.h:3181 [inline]\n kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691\n __sock_release net/socket.c:659 [inline]\n sock_close+0xa4/0x1e8 net/socket.c:1421\n __fput+0x30c/0x738 fs/file_table.c:376\n ____fput+0x20/0x30 fs/file_table.c:404\n task_work_run+0x230/0x2e0 kernel/task_work.c:180\n exit_task_work include/linux/task_work.h:38 [inline]\n do_exit+0x618/0x1f64 kernel/exit.c:871\n do_group_exit+0x194/0x22c kernel/exit.c:1020\n get_signal+0x1500/0x15ec kernel/signal.c:2893\n do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249\n do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148\n exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]\n exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]\n el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713\n el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730\n el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598\n\nAllocated by task 6166:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x40/0x78 mm/kasan/common.c:68\n kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626\n unpoison_slab_object mm/kasan/common.c:314 [inline]\n __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340\n kasan_slab_alloc include/linux/kasan.h:201 [inline]\n slab_post_alloc_hook mm/slub.c:3813 [inline]\n slab_alloc_node mm/slub.c:3860 [inline]\n kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903\n __alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641\n alloc_skb include/linux/skbuff.h:1296 [inline]\n kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783\n sock_sendmsg_nosec net/socket.c:730 [inline]\n __sock_sendmsg net/socket.c:745 [inline]\n sock_sendmsg+0x220/0x2c0 net/socket.c:768\n splice_to_socket+0x7cc/0xd58 fs/splice.c:889\n do_splice_from fs/splice.c:941 [inline]\n direct_splice_actor+0xec/0x1d8 fs/splice.c:1164\n splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108\n do_splice_direct_actor \n---truncated---", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3", "status": "affected", "versionType": "git", "lessThan": "8c9cdbf600143bd6835c8b8351e5ac956da79aec" }, { "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3", "status": "affected", "versionType": "git", "lessThan": "6633b17840bf828921254d788ccd15602843fe9b" }, { "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3", "status": "affected", "versionType": "git", "lessThan": "eb06c8d3022ce6738711191c89f9b3e9cfb91914" }, { "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3", "status": "affected", "versionType": "git", "lessThan": "fa6c23fe6dcac8c8bd63920ee8681292a2bd544e" }, { "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3", "status": "affected", "versionType": "git", "lessThan": "72da240aafb142630cf16adc803ccdacb3780849" }, { "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3", "status": "affected", "versionType": "git", "lessThan": "00425508f30baa5ab6449a1f478480ca7cffa6da" }, { "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3", "status": "affected", "versionType": "git", "lessThan": "9c8d544ed619f704e2b70e63e08ab75630c2ea23" }, { "version": "ab7ac4eb9832e32a09f4e8042705484d2fb0aad3", "status": "affected", "versionType": "git", "lessThan": "807067bf014d4a3ae2cc55bd3de16f22a01eb580" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.6", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.6" }, { "version": "4.19.321", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.19.*" }, { "version": "5.4.283", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.225", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.166", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.107", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.48", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.10.7", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.10.*" }, { "version": "6.11", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }