{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2024-44946", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-08-21T05:34:56.665Z", "datePublished": "2024-08-31T13:22:47.250Z", "dateUpdated": "2024-09-15T17:55:44.111Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-09-15T17:55:44.111Z"}, "descriptions": [{"lang": "en", "value": "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": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/kcm.h", "net/kcm/kcmsock.c"], "versions": [{"version": "ab7ac4eb9832", "lessThan": "8c9cdbf60014", "status": "affected", "versionType": "git"}, {"version": "ab7ac4eb9832", "lessThan": "6633b17840bf", "status": "affected", "versionType": "git"}, {"version": "ab7ac4eb9832", "lessThan": "eb06c8d3022c", "status": "affected", "versionType": "git"}, {"version": "ab7ac4eb9832", "lessThan": "fa6c23fe6dca", "status": "affected", "versionType": "git"}, {"version": "ab7ac4eb9832", "lessThan": "72da240aafb1", "status": "affected", "versionType": "git"}, {"version": "ab7ac4eb9832", "lessThan": "00425508f30b", "status": "affected", "versionType": "git"}, {"version": "ab7ac4eb9832", "lessThan": "9c8d544ed619", "status": "affected", "versionType": "git"}, {"version": "ab7ac4eb9832", "lessThan": "807067bf014d", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/kcm.h", "net/kcm/kcmsock.c"], "versions": [{"version": "4.6", "status": "affected"}, {"version": "0", "lessThan": "4.6", "status": "unaffected", "versionType": "custom"}, {"version": "4.19.321", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "custom"}, {"version": "5.4.283", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "custom"}, {"version": "5.10.225", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom"}, {"version": "5.15.166", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom"}, {"version": "6.1.107", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "custom"}, {"version": "6.6.48", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom"}, {"version": "6.10.7", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "custom"}, {"version": "6.11", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "references": [{"url": "https://git.kernel.org/stable/c/8c9cdbf600143bd6835c8b8351e5ac956da79aec"}, {"url": "https://git.kernel.org/stable/c/6633b17840bf828921254d788ccd15602843fe9b"}, {"url": "https://git.kernel.org/stable/c/eb06c8d3022ce6738711191c89f9b3e9cfb91914"}, {"url": "https://git.kernel.org/stable/c/fa6c23fe6dcac8c8bd63920ee8681292a2bd544e"}, {"url": "https://git.kernel.org/stable/c/72da240aafb142630cf16adc803ccdacb3780849"}, {"url": "https://git.kernel.org/stable/c/00425508f30baa5ab6449a1f478480ca7cffa6da"}, {"url": "https://git.kernel.org/stable/c/9c8d544ed619f704e2b70e63e08ab75630c2ea23"}, {"url": "https://git.kernel.org/stable/c/807067bf014d4a3ae2cc55bd3de16f22a01eb580"}], "title": "kcm: Serialise kcm_sendmsg() for the same socket.", "x_generator": {"engine": "bippy-c9c4e1df01b2"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2024-44946", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-09-10T15:27:06.483265Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-12T17:33:16.399Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2024-44946", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-09-10T15:27:06.483265Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-11T12:42:19.197Z"}}], "cna": {"title": "kcm: Serialise kcm_sendmsg() for the same socket.", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "ab7ac4eb9832", "lessThan": "8c9cdbf60014", "versionType": "git"}, {"status": "affected", "version": "ab7ac4eb9832", "lessThan": "6633b17840bf", "versionType": "git"}, {"status": "affected", "version": "ab7ac4eb9832", "lessThan": "eb06c8d3022c", "versionType": "git"}, {"status": "affected", "version": "ab7ac4eb9832", "lessThan": "fa6c23fe6dca", "versionType": "git"}, {"status": "affected", "version": "ab7ac4eb9832", "lessThan": "72da240aafb1", "versionType": "git"}, {"status": "affected", "version": "ab7ac4eb9832", "lessThan": "00425508f30b", "versionType": "git"}, {"status": "affected", "version": "ab7ac4eb9832", "lessThan": "9c8d544ed619", "versionType": "git"}, {"status": "affected", "version": "ab7ac4eb9832", "lessThan": "807067bf014d", "versionType": "git"}], "programFiles": ["include/net/kcm.h", "net/kcm/kcmsock.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.6"}, {"status": "unaffected", "version": "0", "lessThan": "4.6", "versionType": "custom"}, {"status": "unaffected", "version": "4.19.321", "versionType": "custom", "lessThanOrEqual": "4.19.*"}, {"status": "unaffected", "version": "5.4.283", "versionType": "custom", "lessThanOrEqual": "5.4.*"}, {"status": "unaffected", "version": "5.10.225", "versionType": "custom", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.166", "versionType": "custom", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.107", "versionType": "custom", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.48", "versionType": "custom", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.10.7", "versionType": "custom", "lessThanOrEqual": "6.10.*"}, {"status": "unaffected", "version": "6.11", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["include/net/kcm.h", "net/kcm/kcmsock.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/8c9cdbf600143bd6835c8b8351e5ac956da79aec"}, {"url": "https://git.kernel.org/stable/c/6633b17840bf828921254d788ccd15602843fe9b"}, {"url": "https://git.kernel.org/stable/c/eb06c8d3022ce6738711191c89f9b3e9cfb91914"}, {"url": "https://git.kernel.org/stable/c/fa6c23fe6dcac8c8bd63920ee8681292a2bd544e"}, {"url": "https://git.kernel.org/stable/c/72da240aafb142630cf16adc803ccdacb3780849"}, {"url": "https://git.kernel.org/stable/c/00425508f30baa5ab6449a1f478480ca7cffa6da"}, {"url": "https://git.kernel.org/stable/c/9c8d544ed619f704e2b70e63e08ab75630c2ea23"}, {"url": "https://git.kernel.org/stable/c/807067bf014d4a3ae2cc55bd3de16f22a01eb580"}], "x_generator": {"engine": "bippy-c9c4e1df01b2"}, "descriptions": [{"lang": "en", "value": "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---"}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-09-15T17:55:44.111Z"}}}, "cveMetadata": {"cveId": "CVE-2024-44946", "state": "PUBLISHED", "dateUpdated": "2024-09-15T17:55:44.111Z", "dateReserved": "2024-08-21T05:34:56.665Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-08-31T13:22:47.250Z", "assignerShortName": "Linux"}, "dataVersion": "5.1"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "90446753-6047-4C19-AD2D-8691C846DDB3", "versionEndExcluding": "6.1.107", "versionStartIncluding": "4.6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "9DE9201A-CE6B-4726-BABB-8265EA0F8AE4", "versionEndExcluding": "6.6.48", "versionStartIncluding": "6.2", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "D2AFDFD1-D95A-4EB7-843B-5E7659518B67", "versionEndExcluding": "6.10.7", "versionStartIncluding": "6.7", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*", "matchCriteriaId": "8B3CE743-2126-47A3-8B7C-822B502CF119", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:*", "matchCriteriaId": "4DEB27E7-30AA-45CC-8934-B89263EF3551", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:*", "matchCriteriaId": "E0005AEF-856E-47EB-BFE4-90C46899394D", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:*", "matchCriteriaId": "39889A68-6D34-47A6-82FC-CD0BF23D6754", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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---"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: kcm: serializar kcm_sendmsg() para el mismo socket. syzkaller inform\u00f3 de UAF en kcm_release(). [0] El escenario es 1. El hilo A crea un skb con MSG_MORE y establece kcm->seq_skb. 2. El hilo A reanuda la creaci\u00f3n de skb desde kcm->seq_skb, pero es bloqueado por sk_stream_wait_memory() 3. El hilo B llama a sendmsg() simult\u00e1neamente, termina de crear kcm->seq_skb y coloca el skb en la cola de escritura 4. El hilo A enfrenta un error y finalmente libera el skb que ya est\u00e1 en la cola de escritura 5. kcm_release() libera dos veces el skb en la cola de escritura Cuando un hilo est\u00e1 creando un skb MSG_MORE, otro hilo no debe tocarlo. Agreguemos un mutex por sk y serialicemos kcm_sendmsg(). [0]: BUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline] BUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline] BUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 Read of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167 CPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G B 6.8.0-rc5-syzkaller-g9abbc24128bc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x178/0x518 mm/kasan/report.c:488 kasan_report+0xd8/0x138 mm/kasan/report.c:601 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __skb_unlink include/linux/skbuff.h:2366 [inline] __skb_dequeue include/linux/skbuff.h:2385 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] __skb_queue_purge include/linux/skbuff.h:3181 [inline] kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 __sock_release net/socket.c:659 [inline] sock_close+0xa4/0x1e8 net/socket.c:1421 __fput+0x30c/0x738 fs/file_table.c:376 ____fput+0x20/0x30 fs/file_table.c:404 task_work_run+0x230/0x2e0 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x618/0x1f64 kernel/exit.c:871 do_group_exit+0x194/0x22c kernel/exit.c:1020 get_signal+0x1500/0x15ec kernel/signal.c:2893 do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 Allocated by task 6166: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626 unpoison_slab_object mm/kasan/common.c:314 [inline] __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903 __alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641 alloc_skb include/linux/skbuff.h:1296 [inline] kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_sendmsg+0x220/0x2c0 net/socket.c:768 splice_to_socket+0x7cc/0xd58 fs/splice.c:889 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0xec/0x1d8 fs/splice.c:1164 splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108 do_splice_direct_actor ---truncado---"}], "id": "CVE-2024-44946", "lastModified": "2024-09-04T12:15:05.150", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2024-08-31T14:15:04.320", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/00425508f30baa5ab6449a1f478480ca7cffa6da"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6633b17840bf828921254d788ccd15602843fe9b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/72da240aafb142630cf16adc803ccdacb3780849"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/807067bf014d4a3ae2cc55bd3de16f22a01eb580"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8c9cdbf600143bd6835c8b8351e5ac956da79aec"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/9c8d544ed619f704e2b70e63e08ab75630c2ea23"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/eb06c8d3022ce6738711191c89f9b3e9cfb91914"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fa6c23fe6dcac8c8bd63920ee8681292a2bd544e"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: kcm: Serialise kcm_sendmsg() for the same socket.", "id": "2308807", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2308807"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-416", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nkcm: Serialise kcm_sendmsg() for the same socket.\nsyzkaller reported UAF in kcm_release(). [0]\nThe scenario is\n1. Thread A builds a skb with MSG_MORE and sets kcm->seq_skb.\n2. Thread A resumes building skb from kcm->seq_skb but is blocked\nby sk_stream_wait_memory()\n3. Thread B calls sendmsg() concurrently, finishes building kcm->seq_skb\nand puts the skb to the write queue\n4. Thread A faces an error and finally frees skb that is already in the\nwrite queue\n5. kcm_release() does double-free the skb in the write queue\nWhen a thread is building a MSG_MORE skb, another thread must not touch it.\nLet's add a per-sk mutex and serialise kcm_sendmsg().\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\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:\ndump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291\nshow_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298\n__dump_stack lib/dump_stack.c:88 [inline]\ndump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106\nprint_address_description mm/kasan/report.c:377 [inline]\nprint_report+0x178/0x518 mm/kasan/report.c:488\nkasan_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]\nkcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691\n__sock_release net/socket.c:659 [inline]\nsock_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\ntask_work_run+0x230/0x2e0 kernel/task_work.c:180\nexit_task_work include/linux/task_work.h:38 [inline]\ndo_exit+0x618/0x1f64 kernel/exit.c:871\ndo_group_exit+0x194/0x22c kernel/exit.c:1020\nget_signal+0x1500/0x15ec kernel/signal.c:2893\ndo_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249\ndo_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148\nexit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]\nexit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]\nel0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713\nel0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730\nel0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598\nAllocated by task 6166:\nkasan_save_stack mm/kasan/common.c:47 [inline]\nkasan_save_track+0x40/0x78 mm/kasan/common.c:68\nkasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626\nunpoison_slab_object mm/kasan/common.c:314 [inline]\n__kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340\nkasan_slab_alloc include/linux/kasan.h:201 [inline]\nslab_post_alloc_hook mm/slub.c:3813 [inline]\nslab_alloc_node mm/slub.c:3860 [inline]\nkmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903\n__alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641\nalloc_skb include/linux/skbuff.h:1296 [inline]\nkcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783\nsock_sendmsg_nosec net/socket.c:730 [inline]\n__sock_sendmsg net/socket.c:745 [inline]\nsock_sendmsg+0x220/0x2c0 net/socket.c:768\nsplice_to_socket+0x7cc/0xd58 fs/splice.c:889\ndo_splice_from fs/splice.c:941 [inline]\ndirect_splice_actor+0xec/0x1d8 fs/splice.c:1164\nsplice_direct_to_actor+0x438/0xa0c fs/splice.c:1108\ndo_splice_direct_actor \n---truncated---"], "name": "CVE-2024-44946", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-08-31T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2024-44946\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-44946\nhttps://lore.kernel.org/linux-cve-announce/2024083150-CVE-2024-44946-9cf1@gregkh/T"], "threat_severity": "Moderate"}