{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2024-26676", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-19T14:20:24.151Z", "datePublished": "2024-04-02T07:01:40.758Z", "dateUpdated": "2024-11-05T17:59:44.664Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-05T09:13:41.761Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.\n\nsyzbot reported a warning [0] in __unix_gc() with a repro, which\ncreates a socketpair and sends one socket's fd to itself using the\npeer.\n\n socketpair(AF_UNIX, SOCK_STREAM, 0, [3, 4]) = 0\n sendmsg(4, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base=\"\\360\", iov_len=1}],\n msg_iovlen=1, msg_control=[{cmsg_len=20, cmsg_level=SOL_SOCKET,\n cmsg_type=SCM_RIGHTS, cmsg_data=[3]}],\n msg_controllen=24, msg_flags=0}, MSG_OOB|MSG_PROBE|MSG_DONTWAIT|MSG_ZEROCOPY) = 1\n\nThis forms a self-cyclic reference that GC should finally untangle\nbut does not due to lack of MSG_OOB handling, resulting in memory\nleak.\n\nRecently, commit 11498715f266 (\"af_unix: Remove io_uring code for\nGC.\") removed io_uring's dead code in GC and revealed the problem.\n\nThe code was executed at the final stage of GC and unconditionally\nmoved all GC candidates from gc_candidates to gc_inflight_list.\nThat papered over the reported problem by always making the following\nWARN_ON_ONCE(!list_empty(&gc_candidates)) false.\n\nThe problem has been there since commit 2aab4b969002 (\"af_unix: fix\nstruct pid leaks in OOB support\") added full scm support for MSG_OOB\nwhile fixing another bug.\n\nTo fix this problem, we must call kfree_skb() for unix_sk(sk)->oob_skb\nif the socket still exists in gc_candidates after purging collected skb.\n\nThen, we need to set NULL to oob_skb before calling kfree_skb() because\nit calls last fput() and triggers unix_release_sock(), where we call\nduplicate kfree_skb(u->oob_skb) if not NULL.\n\nNote that the leaked socket remained being linked to a global list, so\nkmemleak also could not detect it. We need to check /proc/net/protocol\nto notice the unfreed socket.\n\n[0]:\nWARNING: CPU: 0 PID: 2863 at net/unix/garbage.c:345 __unix_gc+0xc74/0xe80 net/unix/garbage.c:345\nModules linked in:\nCPU: 0 PID: 2863 Comm: kworker/u4:11 Not tainted 6.8.0-rc1-syzkaller-00583-g1701940b1a02 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024\nWorkqueue: events_unbound __unix_gc\nRIP: 0010:__unix_gc+0xc74/0xe80 net/unix/garbage.c:345\nCode: 8b 5c 24 50 e9 86 f8 ff ff e8 f8 e4 22 f8 31 d2 48 c7 c6 30 6a 69 89 4c 89 ef e8 97 ef ff ff e9 80 f9 ff ff e8 dd e4 22 f8 90 <0f> 0b 90 e9 7b fd ff ff 48 89 df e8 5c e7 7c f8 e9 d3 f8 ff ff e8\nRSP: 0018:ffffc9000b03fba0 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: ffffc9000b03fc10 RCX: ffffffff816c493e\nRDX: ffff88802c02d940 RSI: ffffffff896982f3 RDI: ffffc9000b03fb30\nRBP: ffffc9000b03fce0 R08: 0000000000000001 R09: fffff52001607f66\nR10: 0000000000000003 R11: 0000000000000002 R12: dffffc0000000000\nR13: ffffc9000b03fc10 R14: ffffc9000b03fc10 R15: 0000000000000001\nFS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00005559c8677a60 CR3: 000000000d57a000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n process_one_work+0x889/0x15e0 kernel/workqueue.c:2633\n process_scheduled_works kernel/workqueue.c:2706 [inline]\n worker_thread+0x8b9/0x12a0 kernel/workqueue.c:2787\n kthread+0x2c6/0x3b0 kernel/kthread.c:388\n ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242\n </TASK>"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/unix/garbage.c"], "versions": [{"version": "f3969427fb06", "lessThan": "4fe505c63aa3", "status": "affected", "versionType": "git"}, {"version": "ac1968ac3992", "lessThan": "e0e09186d882", "status": "affected", "versionType": "git"}, {"version": "2aab4b969002", "lessThan": "b74aa9ce13d0", "status": "affected", "versionType": "git"}, {"version": "2aab4b969002", "lessThan": "82ae47c5c3a6", "status": "affected", "versionType": "git"}, {"version": "2aab4b969002", "lessThan": "1279f9d9dec2", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/unix/garbage.c"], "versions": [{"version": "6.3", "status": "affected"}, {"version": "0", "lessThan": "6.3", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.149", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.78", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.17", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.7.5", "lessThanOrEqual": "6.7.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.8", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "references": [{"url": "https://git.kernel.org/stable/c/4fe505c63aa3273135a57597fda761e9aecc7668"}, {"url": "https://git.kernel.org/stable/c/e0e09186d8821ad59806115d347ea32efa43ca4b"}, {"url": "https://git.kernel.org/stable/c/b74aa9ce13d02b7fd37c5325b99854f91b9b4276"}, {"url": "https://git.kernel.org/stable/c/82ae47c5c3a6b27fdc0f9e83c1499cb439c56140"}, {"url": "https://git.kernel.org/stable/c/1279f9d9dec2d7462823a18c29ad61359e0a007d"}], "title": "af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.", "x_generator": {"engine": "bippy-9e1c9544281a"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "lang": "en", "description": "CWE-noinfo Not enough information"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2024-04-02T15:25:42.881633Z", "id": "CVE-2024-26676", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-11-05T17:59:44.664Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T00:14:12.513Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/4fe505c63aa3273135a57597fda761e9aecc7668", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/e0e09186d8821ad59806115d347ea32efa43ca4b", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/b74aa9ce13d02b7fd37c5325b99854f91b9b4276", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/82ae47c5c3a6b27fdc0f9e83c1499cb439c56140", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/1279f9d9dec2d7462823a18c29ad61359e0a007d", "tags": ["x_transferred"]}]}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/4fe505c63aa3273135a57597fda761e9aecc7668", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/e0e09186d8821ad59806115d347ea32efa43ca4b", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/b74aa9ce13d02b7fd37c5325b99854f91b9b4276", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/82ae47c5c3a6b27fdc0f9e83c1499cb439c56140", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/1279f9d9dec2d7462823a18c29ad61359e0a007d", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T00:14:12.513Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2024-26676", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-04-02T15:25:42.881633Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "description": "CWE-noinfo Not enough information"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-05-23T19:01:21.128Z"}}], "cna": {"title": "af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.", "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "f3969427fb06", "lessThan": "4fe505c63aa3", "versionType": "git"}, {"status": "affected", "version": "ac1968ac3992", "lessThan": "e0e09186d882", "versionType": "git"}, {"status": "affected", "version": "2aab4b969002", "lessThan": "b74aa9ce13d0", "versionType": "git"}, {"status": "affected", "version": "2aab4b969002", "lessThan": "82ae47c5c3a6", "versionType": "git"}, {"status": "affected", "version": "2aab4b969002", "lessThan": "1279f9d9dec2", "versionType": "git"}], "programFiles": ["net/unix/garbage.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.3"}, {"status": "unaffected", "version": "0", "lessThan": "6.3", "versionType": "semver"}, {"status": "unaffected", "version": "5.15.149", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.78", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.17", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.7.5", "versionType": "semver", "lessThanOrEqual": "6.7.*"}, {"status": "unaffected", "version": "6.8", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/unix/garbage.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/4fe505c63aa3273135a57597fda761e9aecc7668"}, {"url": "https://git.kernel.org/stable/c/e0e09186d8821ad59806115d347ea32efa43ca4b"}, {"url": "https://git.kernel.org/stable/c/b74aa9ce13d02b7fd37c5325b99854f91b9b4276"}, {"url": "https://git.kernel.org/stable/c/82ae47c5c3a6b27fdc0f9e83c1499cb439c56140"}, {"url": "https://git.kernel.org/stable/c/1279f9d9dec2d7462823a18c29ad61359e0a007d"}], "x_generator": {"engine": "bippy-9e1c9544281a"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.\n\nsyzbot reported a warning [0] in __unix_gc() with a repro, which\ncreates a socketpair and sends one socket's fd to itself using the\npeer.\n\n socketpair(AF_UNIX, SOCK_STREAM, 0, [3, 4]) = 0\n sendmsg(4, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base=\"\\360\", iov_len=1}],\n msg_iovlen=1, msg_control=[{cmsg_len=20, cmsg_level=SOL_SOCKET,\n cmsg_type=SCM_RIGHTS, cmsg_data=[3]}],\n msg_controllen=24, msg_flags=0}, MSG_OOB|MSG_PROBE|MSG_DONTWAIT|MSG_ZEROCOPY) = 1\n\nThis forms a self-cyclic reference that GC should finally untangle\nbut does not due to lack of MSG_OOB handling, resulting in memory\nleak.\n\nRecently, commit 11498715f266 (\"af_unix: Remove io_uring code for\nGC.\") removed io_uring's dead code in GC and revealed the problem.\n\nThe code was executed at the final stage of GC and unconditionally\nmoved all GC candidates from gc_candidates to gc_inflight_list.\nThat papered over the reported problem by always making the following\nWARN_ON_ONCE(!list_empty(&gc_candidates)) false.\n\nThe problem has been there since commit 2aab4b969002 (\"af_unix: fix\nstruct pid leaks in OOB support\") added full scm support for MSG_OOB\nwhile fixing another bug.\n\nTo fix this problem, we must call kfree_skb() for unix_sk(sk)->oob_skb\nif the socket still exists in gc_candidates after purging collected skb.\n\nThen, we need to set NULL to oob_skb before calling kfree_skb() because\nit calls last fput() and triggers unix_release_sock(), where we call\nduplicate kfree_skb(u->oob_skb) if not NULL.\n\nNote that the leaked socket remained being linked to a global list, so\nkmemleak also could not detect it. We need to check /proc/net/protocol\nto notice the unfreed socket.\n\n[0]:\nWARNING: CPU: 0 PID: 2863 at net/unix/garbage.c:345 __unix_gc+0xc74/0xe80 net/unix/garbage.c:345\nModules linked in:\nCPU: 0 PID: 2863 Comm: kworker/u4:11 Not tainted 6.8.0-rc1-syzkaller-00583-g1701940b1a02 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024\nWorkqueue: events_unbound __unix_gc\nRIP: 0010:__unix_gc+0xc74/0xe80 net/unix/garbage.c:345\nCode: 8b 5c 24 50 e9 86 f8 ff ff e8 f8 e4 22 f8 31 d2 48 c7 c6 30 6a 69 89 4c 89 ef e8 97 ef ff ff e9 80 f9 ff ff e8 dd e4 22 f8 90 <0f> 0b 90 e9 7b fd ff ff 48 89 df e8 5c e7 7c f8 e9 d3 f8 ff ff e8\nRSP: 0018:ffffc9000b03fba0 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: ffffc9000b03fc10 RCX: ffffffff816c493e\nRDX: ffff88802c02d940 RSI: ffffffff896982f3 RDI: ffffc9000b03fb30\nRBP: ffffc9000b03fce0 R08: 0000000000000001 R09: fffff52001607f66\nR10: 0000000000000003 R11: 0000000000000002 R12: dffffc0000000000\nR13: ffffc9000b03fc10 R14: ffffc9000b03fc10 R15: 0000000000000001\nFS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00005559c8677a60 CR3: 000000000d57a000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n process_one_work+0x889/0x15e0 kernel/workqueue.c:2633\n process_scheduled_works kernel/workqueue.c:2706 [inline]\n worker_thread+0x8b9/0x12a0 kernel/workqueue.c:2787\n kthread+0x2c6/0x3b0 kernel/kthread.c:388\n ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242\n </TASK>"}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-11-05T09:13:41.761Z"}}}, "cveMetadata": {"cveId": "CVE-2024-26676", "state": "PUBLISHED", "dateUpdated": "2024-11-05T17:59:44.664Z", "dateReserved": "2024-02-19T14:20:24.151Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-04-02T07:01:40.758Z", "assignerShortName": "Linux"}, "dataVersion": "5.1"}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.\n\nsyzbot reported a warning [0] in __unix_gc() with a repro, which\ncreates a socketpair and sends one socket's fd to itself using the\npeer.\n\n socketpair(AF_UNIX, SOCK_STREAM, 0, [3, 4]) = 0\n sendmsg(4, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base=\"\\360\", iov_len=1}],\n msg_iovlen=1, msg_control=[{cmsg_len=20, cmsg_level=SOL_SOCKET,\n cmsg_type=SCM_RIGHTS, cmsg_data=[3]}],\n msg_controllen=24, msg_flags=0}, MSG_OOB|MSG_PROBE|MSG_DONTWAIT|MSG_ZEROCOPY) = 1\n\nThis forms a self-cyclic reference that GC should finally untangle\nbut does not due to lack of MSG_OOB handling, resulting in memory\nleak.\n\nRecently, commit 11498715f266 (\"af_unix: Remove io_uring code for\nGC.\") removed io_uring's dead code in GC and revealed the problem.\n\nThe code was executed at the final stage of GC and unconditionally\nmoved all GC candidates from gc_candidates to gc_inflight_list.\nThat papered over the reported problem by always making the following\nWARN_ON_ONCE(!list_empty(&gc_candidates)) false.\n\nThe problem has been there since commit 2aab4b969002 (\"af_unix: fix\nstruct pid leaks in OOB support\") added full scm support for MSG_OOB\nwhile fixing another bug.\n\nTo fix this problem, we must call kfree_skb() for unix_sk(sk)->oob_skb\nif the socket still exists in gc_candidates after purging collected skb.\n\nThen, we need to set NULL to oob_skb before calling kfree_skb() because\nit calls last fput() and triggers unix_release_sock(), where we call\nduplicate kfree_skb(u->oob_skb) if not NULL.\n\nNote that the leaked socket remained being linked to a global list, so\nkmemleak also could not detect it. We need to check /proc/net/protocol\nto notice the unfreed socket.\n\n[0]:\nWARNING: CPU: 0 PID: 2863 at net/unix/garbage.c:345 __unix_gc+0xc74/0xe80 net/unix/garbage.c:345\nModules linked in:\nCPU: 0 PID: 2863 Comm: kworker/u4:11 Not tainted 6.8.0-rc1-syzkaller-00583-g1701940b1a02 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024\nWorkqueue: events_unbound __unix_gc\nRIP: 0010:__unix_gc+0xc74/0xe80 net/unix/garbage.c:345\nCode: 8b 5c 24 50 e9 86 f8 ff ff e8 f8 e4 22 f8 31 d2 48 c7 c6 30 6a 69 89 4c 89 ef e8 97 ef ff ff e9 80 f9 ff ff e8 dd e4 22 f8 90 <0f> 0b 90 e9 7b fd ff ff 48 89 df e8 5c e7 7c f8 e9 d3 f8 ff ff e8\nRSP: 0018:ffffc9000b03fba0 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: ffffc9000b03fc10 RCX: ffffffff816c493e\nRDX: ffff88802c02d940 RSI: ffffffff896982f3 RDI: ffffc9000b03fb30\nRBP: ffffc9000b03fce0 R08: 0000000000000001 R09: fffff52001607f66\nR10: 0000000000000003 R11: 0000000000000002 R12: dffffc0000000000\nR13: ffffc9000b03fc10 R14: ffffc9000b03fc10 R15: 0000000000000001\nFS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00005559c8677a60 CR3: 000000000d57a000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n process_one_work+0x889/0x15e0 kernel/workqueue.c:2633\n process_scheduled_works kernel/workqueue.c:2706 [inline]\n worker_thread+0x8b9/0x12a0 kernel/workqueue.c:2787\n kthread+0x2c6/0x3b0 kernel/kthread.c:388\n ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242\n </TASK>"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: af_unix: Llame a kfree_skb() para unix_(sk)-&gt;oob_skb muerto en GC. syzbot inform\u00f3 una advertencia [0] en __unix_gc() con una reproducci\u00f3n, que crea un par de sockets y se env\u00eda el fd de un socket a s\u00ed mismo utilizando el par. socketpair(AF_UNIX, SOCK_STREAM, 0, [3, 4]) = 0 sendmsg(4, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base=\"\\360\", iov_len=1}], msg_iovlen=1, msg_control=[{cmsg_len=20, cmsg_level=SOL_SOCKET, cmsg_type=SCM_RIGHTS, cmsg_data=[3]}], msg_controllen=24, msg_flags=0}, MSG_OOB|MSG_PROBE|MSG_DONTWAIT|MSG_ZEROCOPY) = 1 Esto forma una referencia autoc\u00edclica ese GC finalmente deber\u00eda desenredarse, pero no lo hace debido a la falta de manejo de MSG_OOB, lo que resulta en una p\u00e9rdida de memoria. Recientemente, el commit 11498715f266 (\"af_unix: Eliminar el c\u00f3digo io_uring para GC.\") elimin\u00f3 el c\u00f3digo inactivo de io_uring en GC y revel\u00f3 el problema. El c\u00f3digo se ejecut\u00f3 en la etapa final de GC y movi\u00f3 incondicionalmente todos los candidatos de GC de gc_candidates a gc_inflight_list. Eso ocult\u00f3 el problema informado haciendo siempre que lo siguiente WARN_ON_ONCE(!list_empty(&amp;gc_candidates)) fuera falso. El problema ha estado ah\u00ed desde que el commit 2aab4b969002 (\"af_unix: corrige fugas de struct pid en soporte OOB\") agreg\u00f3 soporte completo de scm para MSG_OOB mientras solucionaba otro error. Para solucionar este problema, debemos llamar a kfree_skb() para unix_sk(sk)-&gt;oob_skb si el socket todav\u00eda existe en gc_candidates despu\u00e9s de purgar el skb recopilado. Luego, necesitamos establecer NULL en oob_skb antes de llamar a kfree_skb() porque llama al \u00faltimo fput() y activa unix_release_sock(), donde llamamos al duplicado kfree_skb(u-&gt;oob_skb) si no es NULL. Tenga en cuenta que el socket filtrado segu\u00eda vinculado a una lista global, por lo que kmemleak tampoco pudo detectarlo. Necesitamos verificar /proc/net/protocol para notar el socket no liberado. [0]: ADVERTENCIA: CPU: 0 PID: 2863 en net/unix/garbage.c:345 __unix_gc+0xc74/0xe80 net/unix/garbage.c:345 M\u00f3dulos vinculados en: CPU: 0 PID: 2863 Comm: kworker/ u4:11 No contaminado 6.8.0-rc1-syzkaller-00583-g1701940b1a02 #0 Nombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 25/01/2024 Cola de trabajo: events_unbound __unix_gc RIP: 0010:__unix_gc+0xc74/0xe80 net/unix/garbage.c:345 C\u00f3digo: 8b 5c 24 50 e9 86 f8 ff ff e8 f8 e4 22 f8 31 d2 48 c7 c6 30 6a 69 89 4c 89 ef e8 97 ef ff ff e9 80 f9 ff ff e8 dd e4 22 f8 90 &lt;0f&gt; 0b 90 e9 7b fd ff ff 48 89 df e8 5c e7 7c f8 e9 d3 f8 ff ff e8 RSP: 0018:ffffc9000b03fba0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff c9000b03fc10 RCX: ffffffff816c493e RDX: ffff88802c02d940 RSI: ffffffff896982f3 RDI: ffffc9000b03fb30 RBP: ffffc9000b03fce0 R08: 0000000000000001 R09: fffff52001607f66 R10: 00000000000000003 R11: 00000000000000002 R12: dffffc 0000000000 R13: ffffc9000b03fc10 R14: ffffc9000b03fc10 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:000 0000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005559c8677a60 CR3: 000000000d57a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 00000000 00000000 DR2: 0000000000000000 DR3: 00000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Seguimiento de llamadas: Process_one_work+0x889/0x15e0 kernel/workqueue.c :2633 Process_scheduled_works kernel/workqueue.c:2706 [en l\u00ednea] work_thread+0x8b9/0x12a0 kernel/workqueue.c:2787 kthread+0x2c6/0x3b0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process. c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 "}], "id": "CVE-2024-26676", "lastModified": "2024-11-05T18:35:06.087", "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": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}, "published": "2024-04-02T07:15:44.170", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1279f9d9dec2d7462823a18c29ad61359e0a007d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4fe505c63aa3273135a57597fda761e9aecc7668"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/82ae47c5c3a6b27fdc0f9e83c1499cb439c56140"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b74aa9ce13d02b7fd37c5325b99854f91b9b4276"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e0e09186d8821ad59806115d347ea32efa43ca4b"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC", "id": "2272832", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2272832"}, "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:H/I:N/A:N", "status": "draft"}, "cwe": "CWE-402", "details": ["In the Linux kernel, the following vulnerability has been resolved:\naf_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.\nsyzbot reported a warning [0] in __unix_gc() with a repro, which\ncreates a socketpair and sends one socket's fd to itself using the\npeer.\nsocketpair(AF_UNIX, SOCK_STREAM, 0, [3, 4]) = 0\nsendmsg(4, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base=\"\\360\", iov_len=1}],\nmsg_iovlen=1, msg_control=[{cmsg_len=20, cmsg_level=SOL_SOCKET,\ncmsg_type=SCM_RIGHTS, cmsg_data=[3]}],\nmsg_controllen=24, msg_flags=0}, MSG_OOB|MSG_PROBE|MSG_DONTWAIT|MSG_ZEROCOPY) = 1\nThis forms a self-cyclic reference that GC should finally untangle\nbut does not due to lack of MSG_OOB handling, resulting in memory\nleak.\nRecently, commit 11498715f266 (\"af_unix: Remove io_uring code for\nGC.\") removed io_uring's dead code in GC and revealed the problem.\nThe code was executed at the final stage of GC and unconditionally\nmoved all GC candidates from gc_candidates to gc_inflight_list.\nThat papered over the reported problem by always making the following\nWARN_ON_ONCE(!list_empty(&gc_candidates)) false.\nThe problem has been there since commit 2aab4b969002 (\"af_unix: fix\nstruct pid leaks in OOB support\") added full scm support for MSG_OOB\nwhile fixing another bug.\nTo fix this problem, we must call kfree_skb() for unix_sk(sk)->oob_skb\nif the socket still exists in gc_candidates after purging collected skb.\nThen, we need to set NULL to oob_skb before calling kfree_skb() because\nit calls last fput() and triggers unix_release_sock(), where we call\nduplicate kfree_skb(u->oob_skb) if not NULL.\nNote that the leaked socket remained being linked to a global list, so\nkmemleak also could not detect it. We need to check /proc/net/protocol\nto notice the unfreed socket.\n[0]:\nWARNING: CPU: 0 PID: 2863 at net/unix/garbage.c:345 __unix_gc+0xc74/0xe80 net/unix/garbage.c:345\nModules linked in:\nCPU: 0 PID: 2863 Comm: kworker/u4:11 Not tainted 6.8.0-rc1-syzkaller-00583-g1701940b1a02 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024\nWorkqueue: events_unbound __unix_gc\nRIP: 0010:__unix_gc+0xc74/0xe80 net/unix/garbage.c:345\nCode: 8b 5c 24 50 e9 86 f8 ff ff e8 f8 e4 22 f8 31 d2 48 c7 c6 30 6a 69 89 4c 89 ef e8 97 ef ff ff e9 80 f9 ff ff e8 dd e4 22 f8 90 <0f> 0b 90 e9 7b fd ff ff 48 89 df e8 5c e7 7c f8 e9 d3 f8 ff ff e8\nRSP: 0018:ffffc9000b03fba0 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: ffffc9000b03fc10 RCX: ffffffff816c493e\nRDX: ffff88802c02d940 RSI: ffffffff896982f3 RDI: ffffc9000b03fb30\nRBP: ffffc9000b03fce0 R08: 0000000000000001 R09: fffff52001607f66\nR10: 0000000000000003 R11: 0000000000000002 R12: dffffc0000000000\nR13: ffffc9000b03fc10 R14: ffffc9000b03fc10 R15: 0000000000000001\nFS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00005559c8677a60 CR3: 000000000d57a000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n<TASK>\nprocess_one_work+0x889/0x15e0 kernel/workqueue.c:2633\nprocess_scheduled_works kernel/workqueue.c:2706 [inline]\nworker_thread+0x8b9/0x12a0 kernel/workqueue.c:2787\nkthread+0x2c6/0x3b0 kernel/kthread.c:388\nret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147\nret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242\n</TASK>"], "name": "CVE-2024-26676", "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": "2024-04-02T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2024-26676\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-26676\nhttps://lore.kernel.org/linux-cve-announce/2024040252-CVE-2024-26676-222f@gregkh/T"], "threat_severity": "Low", "upstream_fix": "kernel 5.15.149, kernel 6.1.78, kernel 6.6.17, kernel 6.7.5, kernel 6.8"}