{"api_version":"1","generated_at":"2026-08-05T01:41:31+00:00","cve":"CVE-2025-38475","urls":{"html":"https://cve.report/CVE-2025-38475","api":"https://cve.report/api/cve/CVE-2025-38475.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2025-38475","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-38475"},"summary":{"title":"smc: Fix various oops due to inet_sock type confusion.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmc: Fix various oops due to inet_sock type confusion.\n\nsyzbot reported weird splats [0][1] in cipso_v4_sock_setattr() while\nfreeing inet_sk(sk)->inet_opt.\n\nThe address was freed multiple times even though it was read-only memory.\n\ncipso_v4_sock_setattr() did nothing wrong, and the root cause was type\nconfusion.\n\nThe cited commit made it possible to create smc_sock as an INET socket.\n\nThe issue is that struct smc_sock does not have struct inet_sock as the\nfirst member but hijacks AF_INET and AF_INET6 sk_family, which confuses\nvarious places.\n\nIn this case, inet_sock.inet_opt was actually smc_sock.clcsk_data_ready(),\nwhich is an address of a function in the text segment.\n\n  $ pahole -C inet_sock vmlinux\n  struct inet_sock {\n  ...\n          struct ip_options_rcu *    inet_opt;             /*   784     8 */\n\n  $ pahole -C smc_sock vmlinux\n  struct smc_sock {\n  ...\n          void                       (*clcsk_data_ready)(struct sock *); /*   784     8 */\n\nThe same issue for another field was reported before. [2][3]\n\nAt that time, an ugly hack was suggested [4], but it makes both INET\nand SMC code error-prone and hard to change.\n\nAlso, yet another variant was fixed by a hacky commit 98d4435efcbf3\n(\"net/smc: prevent NULL pointer dereference in txopt_get\").\n\nInstead of papering over the root cause by such hacks, we should not\nallow non-INET socket to reuse the INET infra.\n\nLet's add inet_sock as the first member of smc_sock.\n\n[0]:\nkvfree_call_rcu(): Double-freed call. rcu_head 000000006921da73\nWARNING: CPU: 0 PID: 6718 at mm/slab_common.c:1956 kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955\nModules linked in:\nCPU: 0 UID: 0 PID: 6718 Comm: syz.0.17 Tainted: G        W           6.16.0-rc4-syzkaller-g7482bb149b9f #0 PREEMPT\nTainted: [W]=WARN\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025\npstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\npc : kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955\nlr : kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955\nsp : ffff8000a03a7730\nx29: ffff8000a03a7730 x28: 00000000fffffff5 x27: 1fffe000184823d3\nx26: dfff800000000000 x25: ffff0000c2411e9e x24: ffff0000dd88da00\nx23: ffff8000891ac9a0 x22: 00000000ffffffea x21: ffff8000891ac9a0\nx20: ffff8000891ac9a0 x19: ffff80008afc2480 x18: 00000000ffffffff\nx17: 0000000000000000 x16: ffff80008ae642c8 x15: ffff700011ede14c\nx14: 1ffff00011ede14c x13: 0000000000000004 x12: ffffffffffffffff\nx11: ffff700011ede14c x10: 0000000000ff0100 x9 : 5fa3c1ffaf0ff000\nx8 : 5fa3c1ffaf0ff000 x7 : 0000000000000001 x6 : 0000000000000001\nx5 : ffff8000a03a7078 x4 : ffff80008f766c20 x3 : ffff80008054d360\nx2 : 0000000000000000 x1 : 0000000000000201 x0 : 0000000000000000\nCall trace:\n kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955 (P)\n cipso_v4_sock_setattr+0x2f0/0x3f4 net/ipv4/cipso_ipv4.c:1914\n netlbl_sock_setattr+0x240/0x334 net/netlabel/netlabel_kapi.c:1000\n smack_netlbl_add+0xa8/0x158 security/smack/smack_lsm.c:2581\n smack_inode_setsecurity+0x378/0x430 security/smack/smack_lsm.c:2912\n security_inode_setsecurity+0x118/0x3c0 security/security.c:2706\n __vfs_setxattr_noperm+0x174/0x5c4 fs/xattr.c:251\n __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:295\n vfs_setxattr+0x158/0x2ac fs/xattr.c:321\n do_setxattr fs/xattr.c:636 [inline]\n file_setxattr+0x1b8/0x294 fs/xattr.c:646\n path_setxattrat+0x2ac/0x320 fs/xattr.c:711\n __do_sys_fsetxattr fs/xattr.c:761 [inline]\n __se_sys_fsetxattr fs/xattr.c:758 [inline]\n __arm64_sys_fsetxattr+0xc0/0xdc fs/xattr.c:758\n __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]\n invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49\n el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132\n do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151\n el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879\n el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898\n el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600\n\n[\n---truncated---","state":"PUBLISHED","assigner":"Linux","published_at":"2025-07-28 12:15:29","updated_at":"2026-07-30 06:23:19"},"problem_types":["CWE-476"],"metrics":[{"version":"3.1","source":"nvd@nist.gov","type":"Primary","score":"5.5","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/67a167a6b8b45607bc34aa541d1c75097d18d460","name":"https://git.kernel.org/stable/c/67a167a6b8b45607bc34aa541d1c75097d18d460","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5b02e397929e5b13b969ef1f8e43c7951e2864f5","name":"https://git.kernel.org/stable/c/5b02e397929e5b13b969ef1f8e43c7951e2864f5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/60ada4fe644edaa6c2da97364184b0425e8aeaf5","name":"https://git.kernel.org/stable/c/60ada4fe644edaa6c2da97364184b0425e8aeaf5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-38475","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38475","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d25a92ccae6bed02327b63d138e12e7806830f78 5b02e397929e5b13b969ef1f8e43c7951e2864f5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d25a92ccae6bed02327b63d138e12e7806830f78 67a167a6b8b45607bc34aa541d1c75097d18d460 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d25a92ccae6bed02327b63d138e12e7806830f78 60ada4fe644edaa6c2da97364184b0425e8aeaf5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.11","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.40 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.15.8 6.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.16 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2025","cve_id":"38475","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"linux","cpe5":"linux_kernel","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/smc/af_smc.c","net/smc/smc.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"5b02e397929e5b13b969ef1f8e43c7951e2864f5","status":"affected","version":"d25a92ccae6bed02327b63d138e12e7806830f78","versionType":"git"},{"lessThan":"67a167a6b8b45607bc34aa541d1c75097d18d460","status":"affected","version":"d25a92ccae6bed02327b63d138e12e7806830f78","versionType":"git"},{"lessThan":"60ada4fe644edaa6c2da97364184b0425e8aeaf5","status":"affected","version":"d25a92ccae6bed02327b63d138e12e7806830f78","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/smc/af_smc.c","net/smc/smc.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.11"},{"lessThan":"6.11","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.40","versionType":"semver"},{"lessThanOrEqual":"6.15.*","status":"unaffected","version":"6.15.8","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.16","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.40","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.15.8","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.16","versionStartIncluding":"6.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmc: Fix various oops due to inet_sock type confusion.\n\nsyzbot reported weird splats [0][1] in cipso_v4_sock_setattr() while\nfreeing inet_sk(sk)->inet_opt.\n\nThe address was freed multiple times even though it was read-only memory.\n\ncipso_v4_sock_setattr() did nothing wrong, and the root cause was type\nconfusion.\n\nThe cited commit made it possible to create smc_sock as an INET socket.\n\nThe issue is that struct smc_sock does not have struct inet_sock as the\nfirst member but hijacks AF_INET and AF_INET6 sk_family, which confuses\nvarious places.\n\nIn this case, inet_sock.inet_opt was actually smc_sock.clcsk_data_ready(),\nwhich is an address of a function in the text segment.\n\n  $ pahole -C inet_sock vmlinux\n  struct inet_sock {\n  ...\n          struct ip_options_rcu *    inet_opt;             /*   784     8 */\n\n  $ pahole -C smc_sock vmlinux\n  struct smc_sock {\n  ...\n          void                       (*clcsk_data_ready)(struct sock *); /*   784     8 */\n\nThe same issue for another field was reported before. [2][3]\n\nAt that time, an ugly hack was suggested [4], but it makes both INET\nand SMC code error-prone and hard to change.\n\nAlso, yet another variant was fixed by a hacky commit 98d4435efcbf3\n(\"net/smc: prevent NULL pointer dereference in txopt_get\").\n\nInstead of papering over the root cause by such hacks, we should not\nallow non-INET socket to reuse the INET infra.\n\nLet's add inet_sock as the first member of smc_sock.\n\n[0]:\nkvfree_call_rcu(): Double-freed call. rcu_head 000000006921da73\nWARNING: CPU: 0 PID: 6718 at mm/slab_common.c:1956 kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955\nModules linked in:\nCPU: 0 UID: 0 PID: 6718 Comm: syz.0.17 Tainted: G        W           6.16.0-rc4-syzkaller-g7482bb149b9f #0 PREEMPT\nTainted: [W]=WARN\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025\npstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\npc : kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955\nlr : kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955\nsp : ffff8000a03a7730\nx29: ffff8000a03a7730 x28: 00000000fffffff5 x27: 1fffe000184823d3\nx26: dfff800000000000 x25: ffff0000c2411e9e x24: ffff0000dd88da00\nx23: ffff8000891ac9a0 x22: 00000000ffffffea x21: ffff8000891ac9a0\nx20: ffff8000891ac9a0 x19: ffff80008afc2480 x18: 00000000ffffffff\nx17: 0000000000000000 x16: ffff80008ae642c8 x15: ffff700011ede14c\nx14: 1ffff00011ede14c x13: 0000000000000004 x12: ffffffffffffffff\nx11: ffff700011ede14c x10: 0000000000ff0100 x9 : 5fa3c1ffaf0ff000\nx8 : 5fa3c1ffaf0ff000 x7 : 0000000000000001 x6 : 0000000000000001\nx5 : ffff8000a03a7078 x4 : ffff80008f766c20 x3 : ffff80008054d360\nx2 : 0000000000000000 x1 : 0000000000000201 x0 : 0000000000000000\nCall trace:\n kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955 (P)\n cipso_v4_sock_setattr+0x2f0/0x3f4 net/ipv4/cipso_ipv4.c:1914\n netlbl_sock_setattr+0x240/0x334 net/netlabel/netlabel_kapi.c:1000\n smack_netlbl_add+0xa8/0x158 security/smack/smack_lsm.c:2581\n smack_inode_setsecurity+0x378/0x430 security/smack/smack_lsm.c:2912\n security_inode_setsecurity+0x118/0x3c0 security/security.c:2706\n __vfs_setxattr_noperm+0x174/0x5c4 fs/xattr.c:251\n __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:295\n vfs_setxattr+0x158/0x2ac fs/xattr.c:321\n do_setxattr fs/xattr.c:636 [inline]\n file_setxattr+0x1b8/0x294 fs/xattr.c:646\n path_setxattrat+0x2ac/0x320 fs/xattr.c:711\n __do_sys_fsetxattr fs/xattr.c:761 [inline]\n __se_sys_fsetxattr fs/xattr.c:758 [inline]\n __arm64_sys_fsetxattr+0xc0/0xdc fs/xattr.c:758\n __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]\n invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49\n el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132\n do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151\n el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879\n el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898\n el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600\n\n[\n---truncated---"}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-30T05:54:30.338Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/5b02e397929e5b13b969ef1f8e43c7951e2864f5"},{"url":"https://git.kernel.org/stable/c/67a167a6b8b45607bc34aa541d1c75097d18d460"},{"url":"https://git.kernel.org/stable/c/60ada4fe644edaa6c2da97364184b0425e8aeaf5"}],"title":"smc: Fix various oops due to inet_sock type confusion.","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2025-38475","datePublished":"2025-07-28T11:21:36.293Z","dateReserved":"2025-04-16T04:51:24.021Z","dateUpdated":"2026-07-30T05:54:30.338Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2025-07-28 12:15:29","lastModifiedDate":"2026-07-30 06:23:19","problem_types":["CWE-476"],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":3.6}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.12.40","matchCriteriaId":"07851087-B8D6-4B99-A561-2A80E0F1FA64"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.15.8","matchCriteriaId":"C7AFE5B0-F3B1-4D30-B8BF-EDA0385C4746"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*","matchCriteriaId":"6D4894DB-CCFE-4602-B1BF-3960B2E19A01"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:*","matchCriteriaId":"09709862-E348-4378-8632-5A7813EDDC86"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:*","matchCriteriaId":"415BF58A-8197-43F5-B3D7-D1D63057A26E"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.16:rc4:*:*:*:*:*:*","matchCriteriaId":"A0517869-312D-4429-80C2-561086E1421C"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.16:rc5:*:*:*:*:*:*","matchCriteriaId":"85421F4E-C863-4ABF-B4B4-E887CC2F7F92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.16:rc6:*:*:*:*:*:*","matchCriteriaId":"3827F0D4-5FEE-4181-B267-5A45E7CA11FC"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2025","CveId":"38475","Ordinal":"1","Title":"smc: Fix various oops due to inet_sock type confusion.","CVE":"CVE-2025-38475","Year":"2025"},"notes":[{"CveYear":"2025","CveId":"38475","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmc: Fix various oops due to inet_sock type confusion.\n\nsyzbot reported weird splats [0][1] in cipso_v4_sock_setattr() while\nfreeing inet_sk(sk)->inet_opt.\n\nThe address was freed multiple times even though it was read-only memory.\n\ncipso_v4_sock_setattr() did nothing wrong, and the root cause was type\nconfusion.\n\nThe cited commit made it possible to create smc_sock as an INET socket.\n\nThe issue is that struct smc_sock does not have struct inet_sock as the\nfirst member but hijacks AF_INET and AF_INET6 sk_family, which confuses\nvarious places.\n\nIn this case, inet_sock.inet_opt was actually smc_sock.clcsk_data_ready(),\nwhich is an address of a function in the text segment.\n\n  $ pahole -C inet_sock vmlinux\n  struct inet_sock {\n  ...\n          struct ip_options_rcu *    inet_opt;             /*   784     8 */\n\n  $ pahole -C smc_sock vmlinux\n  struct smc_sock {\n  ...\n          void                       (*clcsk_data_ready)(struct sock *); /*   784     8 */\n\nThe same issue for another field was reported before. [2][3]\n\nAt that time, an ugly hack was suggested [4], but it makes both INET\nand SMC code error-prone and hard to change.\n\nAlso, yet another variant was fixed by a hacky commit 98d4435efcbf3\n(\"net/smc: prevent NULL pointer dereference in txopt_get\").\n\nInstead of papering over the root cause by such hacks, we should not\nallow non-INET socket to reuse the INET infra.\n\nLet's add inet_sock as the first member of smc_sock.\n\n[0]:\nkvfree_call_rcu(): Double-freed call. rcu_head 000000006921da73\nWARNING: CPU: 0 PID: 6718 at mm/slab_common.c:1956 kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955\nModules linked in:\nCPU: 0 UID: 0 PID: 6718 Comm: syz.0.17 Tainted: G        W           6.16.0-rc4-syzkaller-g7482bb149b9f #0 PREEMPT\nTainted: [W]=WARN\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025\npstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\npc : kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955\nlr : kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955\nsp : ffff8000a03a7730\nx29: ffff8000a03a7730 x28: 00000000fffffff5 x27: 1fffe000184823d3\nx26: dfff800000000000 x25: ffff0000c2411e9e x24: ffff0000dd88da00\nx23: ffff8000891ac9a0 x22: 00000000ffffffea x21: ffff8000891ac9a0\nx20: ffff8000891ac9a0 x19: ffff80008afc2480 x18: 00000000ffffffff\nx17: 0000000000000000 x16: ffff80008ae642c8 x15: ffff700011ede14c\nx14: 1ffff00011ede14c x13: 0000000000000004 x12: ffffffffffffffff\nx11: ffff700011ede14c x10: 0000000000ff0100 x9 : 5fa3c1ffaf0ff000\nx8 : 5fa3c1ffaf0ff000 x7 : 0000000000000001 x6 : 0000000000000001\nx5 : ffff8000a03a7078 x4 : ffff80008f766c20 x3 : ffff80008054d360\nx2 : 0000000000000000 x1 : 0000000000000201 x0 : 0000000000000000\nCall trace:\n kvfree_call_rcu+0x94/0x3f0 mm/slab_common.c:1955 (P)\n cipso_v4_sock_setattr+0x2f0/0x3f4 net/ipv4/cipso_ipv4.c:1914\n netlbl_sock_setattr+0x240/0x334 net/netlabel/netlabel_kapi.c:1000\n smack_netlbl_add+0xa8/0x158 security/smack/smack_lsm.c:2581\n smack_inode_setsecurity+0x378/0x430 security/smack/smack_lsm.c:2912\n security_inode_setsecurity+0x118/0x3c0 security/security.c:2706\n __vfs_setxattr_noperm+0x174/0x5c4 fs/xattr.c:251\n __vfs_setxattr_locked+0x1ec/0x218 fs/xattr.c:295\n vfs_setxattr+0x158/0x2ac fs/xattr.c:321\n do_setxattr fs/xattr.c:636 [inline]\n file_setxattr+0x1b8/0x294 fs/xattr.c:646\n path_setxattrat+0x2ac/0x320 fs/xattr.c:711\n __do_sys_fsetxattr fs/xattr.c:761 [inline]\n __se_sys_fsetxattr fs/xattr.c:758 [inline]\n __arm64_sys_fsetxattr+0xc0/0xdc fs/xattr.c:758\n __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]\n invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49\n el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132\n do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151\n el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879\n el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898\n el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600\n\n[\n---truncated---","Type":"Description","Title":"smc: Fix various oops due to inet_sock type confusion."}]}}}