CVE-2026-68187 - Vulnerability Details

Vendors	Products
Linux	Linux Kernel

Vendors	Products
Linux	Linux Kernel

Link	Providers
https://git.kernel.org/stable/c/16cc4f5c1c4b9e45eca7f7deefa5410a292db599
https://git.kernel.org/stable/c/2bc6bf70d41055377f390d06f0f3521deb62fd3b
https://git.kernel.org/stable/c/55fa2c7f2b15583d1a2fe1b5abcc24377359339f
https://git.kernel.org/stable/c/c62bb00caba66e01fb578d5f0302f247dc64930a
https://git.kernel.org/stable/c/dfc2a00742af4cb7251c1a8fbce4fbae3cc0de4e

Type	Values Removed	Values Added
Weaknesses		CWE-119 CWE-193

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: exec: fix unsigned loop counter wrap in transfer_args_to_stack() The stop value is derived from bprm->p >> PAGE_SHIFT. The index variable is an unsigned long. If bprm->p drops below PAGE_SIZE and stop becomes zero the loop condition index >= stop is always true. After the index == 0 iteration the decrement wraps to ULONG_MAX and bprm->page[ULONG_MAX] reads sizeof(void ) bytes in front of the array. The pointer has wrapped to -1. That garbage pointer is then passed to kmap_local_page() and PAGE_SIZE bytes are copied from wherever that lands into the stack of the process being created. And the loop doesn't terminate either... Getting there only requires bprm->p < PAGE_SIZE. On !MMU bprm_set_stack_limit() and bprm_hit_stack_limit() are empty. So the only constraint on how far bprm->p is pushed down is valid_arg_len(), i.e. that each individual string still fits in what is left. bprm->p starts at PAGE_SIZE MAX_ARG_PAGES - sizeof(void *) so a single argument or environment string of a little over 31 pages leaves it in the first page: Oops - load access fault [#1] CPU: 0 UID: 0 PID: 1 Comm: victim Not tainted 7.2.0-rc4 #1 epc : __memcpy+0xd4/0xf8 ra : transfer_args_to_stack+0xaa/0xae s4 : ffffffffffffffff s2 : 0000000000000000 a1 : ffffffdc98000000 a2 : 0000000000001000 status: 0000000a00001880 badaddr: ffffffdc98000000 cause: 0000000000000005 [<801a5324>] __memcpy+0xd4/0xf8 [<800d5f6a>] load_flat_binary+0x43a/0x65e [<800a2de4>] bprm_execve+0x1d4/0x316 [<800a351a>] do_execveat_common+0x12e/0x138 [<800a3d44>] __riscv_sys_execve+0x38/0x4e Kernel panic - not syncing: Fatal exception in interrupt This is an arcane bug but we should still fix it. Count down from MAX_ARG_PAGES so the loop ends when index reaches stop, stop == 0 included. The iterations performed are unchanged for every other value of stop. Only CONFIG_MMU=n builds are affected, transfer_args_to_stack() is used by binfmt_flat and binfmt_elf_fdpic on nommu only. The loop predates git history. commit 7e7ec6a93434 ("elf_fdpic_transfer_args_to_stack(): make it generic") only moved it from binfmt_elf_fdpic.c into fs/exec.c and narrowed the copy to the used part of the first page. The condition and the decrement are unchanged from 2.6.12-rc2.
Title		exec: fix unsigned loop counter wrap in transfer_args_to_stack()
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/16cc4f5c1c4b9e45eca7f7deefa5410a292db599 https://git.kernel.org/stable/c/2bc6bf70d41055377f390d06f0f3521deb62fd3b https://git.kernel.org/stable/c/55fa2c7f2b15583d1a2fe1b5abcc24377359339f https://git.kernel.org/stable/c/c62bb00caba66e01fb578d5f0302f247dc64930a https://git.kernel.org/stable/c/dfc2a00742af4cb7251c1a8fbce4fbae3cc0de4e

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-68187", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.373Z", "datePublished": "2026-08-10T11:59:59.303Z", "dateUpdated": "2026-08-10T11:59:59.303Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-10T11:59:59.303Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nexec: fix unsigned loop counter wrap in transfer_args_to_stack()\n\nThe stop value is derived from bprm->p >> PAGE_SHIFT. The index variable\nis an unsigned long. If bprm->p drops below PAGE_SIZE and stop becomes\nzero the loop condition index >= stop is always true.\n\nAfter the index == 0 iteration the decrement wraps to ULONG_MAX and\nbprm->page[ULONG_MAX] reads sizeof(void *) bytes in front of the array.\nThe pointer has wrapped to -1. That garbage pointer is then passed to\nkmap_local_page() and PAGE_SIZE bytes are copied from wherever that\nlands into the stack of the process being created. And the loop doesn't\nterminate either...\n\nGetting there only requires bprm->p < PAGE_SIZE. On !MMU\nbprm_set_stack_limit() and bprm_hit_stack_limit() are empty. So the only\nconstraint on how far bprm->p is pushed down is valid_arg_len(), i.e.\nthat each individual string still fits in what is left.\n\nbprm->p starts at PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *) so a\nsingle argument or environment string of a little over 31 pages leaves\nit in the first page:\n\n Oops - load access fault [#1]\n CPU: 0 UID: 0 PID: 1 Comm: victim Not tainted 7.2.0-rc4 #1\n epc : __memcpy+0xd4/0xf8\n ra : transfer_args_to_stack+0xaa/0xae\n s4 : ffffffffffffffff s2 : 0000000000000000\n a1 : ffffffdc98000000 a2 : 0000000000001000\n status: 0000000a00001880 badaddr: ffffffdc98000000 cause: 0000000000000005\n [<801a5324>] __memcpy+0xd4/0xf8\n [<800d5f6a>] load_flat_binary+0x43a/0x65e\n [<800a2de4>] bprm_execve+0x1d4/0x316\n [<800a351a>] do_execveat_common+0x12e/0x138\n [<800a3d44>] __riscv_sys_execve+0x38/0x4e\n Kernel panic - not syncing: Fatal exception in interrupt\n\nThis is an arcane bug but we should still fix it.\n\nCount down from MAX_ARG_PAGES so the loop ends when index reaches stop,\nstop == 0 included. The iterations performed are unchanged for every\nother value of stop.\n\nOnly CONFIG_MMU=n builds are affected, transfer_args_to_stack() is used\nby binfmt_flat and binfmt_elf_fdpic on nommu only.\n\nThe loop predates git history. commit 7e7ec6a93434\n(\"elf_fdpic_transfer_args_to_stack(): make it generic\") only moved it\nfrom binfmt_elf_fdpic.c into fs/exec.c and narrowed the copy to the used\npart of the first page. The condition and the decrement are unchanged\nfrom 2.6.12-rc2."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/exec.c"], "versions": [{"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "c62bb00caba66e01fb578d5f0302f247dc64930a", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "dfc2a00742af4cb7251c1a8fbce4fbae3cc0de4e", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "2bc6bf70d41055377f390d06f0f3521deb62fd3b", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "55fa2c7f2b15583d1a2fe1b5abcc24377359339f", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "16cc4f5c1c4b9e45eca7f7deefa5410a292db599", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/exec.c"], "versions": [{"version": "2.6.12", "status": "affected"}, {"version": "0", "lessThan": "2.6.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2-rc5", "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": "2.6.12", "versionEndExcluding": "6.6.148"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.12.101"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.18.42"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "7.1.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "7.2-rc5"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/c62bb00caba66e01fb578d5f0302f247dc64930a"}, {"url": "https://git.kernel.org/stable/c/dfc2a00742af4cb7251c1a8fbce4fbae3cc0de4e"}, {"url": "https://git.kernel.org/stable/c/2bc6bf70d41055377f390d06f0f3521deb62fd3b"}, {"url": "https://git.kernel.org/stable/c/55fa2c7f2b15583d1a2fe1b5abcc24377359339f"}, {"url": "https://git.kernel.org/stable/c/16cc4f5c1c4b9e45eca7f7deefa5410a292db599"}], "title": "exec: fix unsigned loop counter wrap in transfer_args_to_stack()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,c62bb00caba66e01fb578d5f0302f247dc64930a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,dfc2a00742af4cb7251c1a8fbce4fbae3cc0de4e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,2bc6bf70d41055377f390d06f0f3521deb62fd3b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,55fa2c7f2b15583d1a2fe1b5abcc24377359339f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,16cc4f5c1c4b9e45eca7f7deefa5410a292db599)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "2.6.12"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,2.6.12)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.148,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.101,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.42,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.6,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc5,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-10T14:30:04.129543+00:00", "updated": "2026-08-10T17:15:02.919281+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-119", "CWE-193"]}

Metrics

Affected Vendors & Products

Metrics

Affected Vendors & Products

JSON object

JSON object

JSON object

JSON object

JSON object