{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23107", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.967Z", "datePublished": "2026-02-04T16:08:27.755Z", "dateUpdated": "2026-05-11T22:00:15.573Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T22:00:15.573Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64/fpsimd: signal: Allocate SSVE storage when restoring ZA\n\nThe code to restore a ZA context doesn't attempt to allocate the task's\nsve_state before setting TIF_SME. Consequently, restoring a ZA context\ncan place a task into an invalid state where TIF_SME is set but the\ntask's sve_state is NULL.\n\nIn legitimate but uncommon cases where the ZA signal context was NOT\ncreated by the kernel in the context of the same task (e.g. if the task\nis saved/restored with something like CRIU), we have no guarantee that\nsve_state had been allocated previously. In these cases, userspace can\nenter streaming mode without trapping while sve_state is NULL, causing a\nlater NULL pointer dereference when the kernel attempts to store the\nregister state:\n\n| # ./sigreturn-za\n| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000\n| Mem abort info:\n| ESR = 0x0000000096000046\n| EC = 0x25: DABT (current EL), IL = 32 bits\n| SET = 0, FnV = 0\n| EA = 0, S1PTW = 0\n| FSC = 0x06: level 2 translation fault\n| Data abort info:\n| ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000\n| CM = 0, WnR = 1, TnD = 0, TagAccess = 0\n| GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0\n| user pgtable: 4k pages, 52-bit VAs, pgdp=0000000101f47c00\n| [0000000000000000] pgd=08000001021d8403, p4d=0800000102274403, pud=0800000102275403, pmd=0000000000000000\n| Internal error: Oops: 0000000096000046 [#1] SMP\n| Modules linked in:\n| CPU: 0 UID: 0 PID: 153 Comm: sigreturn-za Not tainted 6.19.0-rc1 #1 PREEMPT\n| Hardware name: linux,dummy-virt (DT)\n| pstate: 214000c9 (nzCv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--)\n| pc : sve_save_state+0x4/0xf0\n| lr : fpsimd_save_user_state+0xb0/0x1c0\n| sp : ffff80008070bcc0\n| x29: ffff80008070bcc0 x28: fff00000c1ca4c40 x27: 63cfa172fb5cf658\n| x26: fff00000c1ca5228 x25: 0000000000000000 x24: 0000000000000000\n| x23: 0000000000000000 x22: fff00000c1ca4c40 x21: fff00000c1ca4c40\n| x20: 0000000000000020 x19: fff00000ff6900f0 x18: 0000000000000000\n| x17: fff05e8e0311f000 x16: 0000000000000000 x15: 028fca8f3bdaf21c\n| x14: 0000000000000212 x13: fff00000c0209f10 x12: 0000000000000020\n| x11: 0000000000200b20 x10: 0000000000000000 x9 : fff00000ff69dcc0\n| x8 : 00000000000003f2 x7 : 0000000000000001 x6 : fff00000c1ca5b48\n| x5 : fff05e8e0311f000 x4 : 0000000008000000 x3 : 0000000000000000\n| x2 : 0000000000000001 x1 : fff00000c1ca5970 x0 : 0000000000000440\n| Call trace:\n| sve_save_state+0x4/0xf0 (P)\n| fpsimd_thread_switch+0x48/0x198\n| __switch_to+0x20/0x1c0\n| __schedule+0x36c/0xce0\n| schedule+0x34/0x11c\n| exit_to_user_mode_loop+0x124/0x188\n| el0_interrupt+0xc8/0xd8\n| __el0_irq_handler_common+0x18/0x24\n| el0t_64_irq_handler+0x10/0x1c\n| el0t_64_irq+0x198/0x19c\n| Code: 54000040 d51b4408 d65f03c0 d503245f (e5bb5800)\n| ---[ end trace 0000000000000000 ]---\n\nFix this by having restore_za_context() ensure that the task's sve_state\nis allocated, matching what we do when taking an SME trap. Any live\nSVE/SSVE state (which is restored earlier from a separate signal\ncontext) must be preserved, and hence this is not zeroed." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/arm64/kernel/signal.c" ], "versions": [ { "version": "39782210eb7e87634d96cacb6ece370bc59d74ba", "lessThan": "c5a5b150992ebab779c1ce54f54676786e47e94c", "status": "affected", "versionType": "git" }, { "version": "39782210eb7e87634d96cacb6ece370bc59d74ba", "lessThan": "19b2c3f3ca1b4b6dccd2a42aca2692d8c79c4214", "status": "affected", "versionType": "git" }, { "version": "39782210eb7e87634d96cacb6ece370bc59d74ba", "lessThan": "0af233d66eff90fb8f3e0fc09f2316bba0b72bb9", "status": "affected", "versionType": "git" }, { "version": "39782210eb7e87634d96cacb6ece370bc59d74ba", "lessThan": "70f7f54566afc23f2c71bf1411af81f5d8009e0f", "status": "affected", "versionType": "git" }, { "version": "39782210eb7e87634d96cacb6ece370bc59d74ba", "lessThan": "ea8ccfddbce0bee6310da4f3fc560ad520f5e6b4", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/arm64/kernel/signal.c" ], "versions": [ { "version": "5.19", "status": "affected" }, { "version": "0", "lessThan": "5.19", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.162", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.122", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.68", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.8", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.1.162" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.6.122" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.12.68" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.18.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c5a5b150992ebab779c1ce54f54676786e47e94c" }, { "url": "https://git.kernel.org/stable/c/19b2c3f3ca1b4b6dccd2a42aca2692d8c79c4214" }, { "url": "https://git.kernel.org/stable/c/0af233d66eff90fb8f3e0fc09f2316bba0b72bb9" }, { "url": "https://git.kernel.org/stable/c/70f7f54566afc23f2c71bf1411af81f5d8009e0f" }, { "url": "https://git.kernel.org/stable/c/ea8ccfddbce0bee6310da4f3fc560ad520f5e6b4" } ], "title": "arm64/fpsimd: signal: Allocate SSVE storage when restoring ZA", "x_generator": { "engine": "bippy-1.2.0" } } } }