{"id":"CVE-2026-98588","state":"PUBLISHED","title":"bpf, sockmap: Reject max_entries > INT_MAX in sock_map_alloc","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Reject max_entries > INT_MAX in sock_map_alloc\n\nsock_map_alloc() only rejects max_entries == 0 and otherwise allows any\nu32 value.  sock_map_free() then walks the sks[] array with a signed int\niterator:\n\n\tint i;\n\tfor (i = 0; i < stab->map.max_entries; i++)\n\t\tstruct sock **psk = &stab->sks[i];\n\nWhen a SOCKMAP is created with max_entries = 0xffffffff (UINT_MAX), the\nallocation of 32 GiB can succeed on large-memory hosts.  During free the\ncounter reaches 0x80000000, wraps to INT_MIN, is sign-extended by movslq\nand turned into a ~16 GiB negative offset from stab->sks, pointing far\nbelow the allocation.\n\nThe faulting access is an xchg() write in sock_map_free().  Without\nKASAN, the same out-of-bounds write can fault on an unmapped vmalloc page\nor corrupt an unrelated allocation if that vmalloc address is populated.\nOn a KASAN kernel with CONFIG_KASAN_VMALLOC=y, the shadow check for that\naddress hits an unmapped shadow page and oopses first:\n\n  BUG: unable to handle page fault for address: fffff521b59c5a00\n  RIP: 0010:kasan_check_range+0x107/0x190\n  Call Trace:\n   sock_map_free+0x93/0x190\n   map_create+0x68d/0xb30\n   __sys_bpf+0x21e/0x2e70\n\nVmcore confirmed stab->map.max_entries == 0xffffffff, stab->sks ==\n0xffffc911ace2d000, and the faulting address sks + (s64)INT_MIN * 8\nexactly at 0xffffc90dace2d000.  The same buggy path is reached on the\nnormal close()/bpf_map_free_deferred() path whenever such a map is\ndestroyed.\n\nsock_map_alloc() used to bound its allocation size through\nbpf_map_charge_init(), but the bound was dropped when rlimit-based memory\naccounting was removed.  Reject max_entries > INT_MAX at creation time so\nthe signed iterator in sock_map_free() never sees a value that would\noverflow.\n\nTriggered by syzkaller and reproduced on both a 6.6-based KASAN kernel\nand the upstream v7.3-rc2 kernel.","publishedAt":"2026-10-18T15:19:00.934Z","updatedAt":"2026-10-19T09:22:13.833Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"f4a73f49e256bd835368504462be3b57b03febff","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"c56191af3a578b9cc265fa3bd5fc0752c59c1781","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"909f761868fda329dc69130ef9eb5b5795bcdf00","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"cc70972ddbf0e3398f2f32624d31db78594d50d8","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"cea597519b9ca6d691c98d92460ead8ece2a07af","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"ba7d627dbc67d62df2fa66d7b41e743c3ace0ec8","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"814a81c842bd88f6bd8a4ce550d560df071a5d03","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock_map.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock_map.c"]}],"references":["https://git.kernel.org/stable/c/f4a73f49e256bd835368504462be3b57b03febff","https://git.kernel.org/stable/c/c56191af3a578b9cc265fa3bd5fc0752c59c1781","https://git.kernel.org/stable/c/909f761868fda329dc69130ef9eb5b5795bcdf00","https://git.kernel.org/stable/c/cc70972ddbf0e3398f2f32624d31db78594d50d8","https://git.kernel.org/stable/c/cea597519b9ca6d691c98d92460ead8ece2a07af","https://git.kernel.org/stable/c/ba7d627dbc67d62df2fa66d7b41e743c3ace0ec8","https://git.kernel.org/stable/c/814a81c842bd88f6bd8a4ce550d560df071a5d03"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98588.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98588","state":"PUBLISHED","datePublished":"2026-10-18T15:19:00.934Z","dateUpdated":"2026-10-19T09:22:13.833Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.358Z"},"containers":{"cna":{"title":"bpf, sockmap: Reject max_entries > INT_MAX in sock_map_alloc","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Reject max_entries > INT_MAX in sock_map_alloc\n\nsock_map_alloc() only rejects max_entries == 0 and otherwise allows any\nu32 value.  sock_map_free() then walks the sks[] array with a signed int\niterator:\n\n\tint i;\n\tfor (i = 0; i < stab->map.max_entries; i++)\n\t\tstruct sock **psk = &stab->sks[i];\n\nWhen a SOCKMAP is created with max_entries = 0xffffffff (UINT_MAX), the\nallocation of 32 GiB can succeed on large-memory hosts.  During free the\ncounter reaches 0x80000000, wraps to INT_MIN, is sign-extended by movslq\nand turned into a ~16 GiB negative offset from stab->sks, pointing far\nbelow the allocation.\n\nThe faulting access is an xchg() write in sock_map_free().  Without\nKASAN, the same out-of-bounds write can fault on an unmapped vmalloc page\nor corrupt an unrelated allocation if that vmalloc address is populated.\nOn a KASAN kernel with CONFIG_KASAN_VMALLOC=y, the shadow check for that\naddress hits an unmapped shadow page and oopses first:\n\n  BUG: unable to handle page fault for address: fffff521b59c5a00\n  RIP: 0010:kasan_check_range+0x107/0x190\n  Call Trace:\n   sock_map_free+0x93/0x190\n   map_create+0x68d/0xb30\n   __sys_bpf+0x21e/0x2e70\n\nVmcore confirmed stab->map.max_entries == 0xffffffff, stab->sks ==\n0xffffc911ace2d000, and the faulting address sks + (s64)INT_MIN * 8\nexactly at 0xffffc90dace2d000.  The same buggy path is reached on the\nnormal close()/bpf_map_free_deferred() path whenever such a map is\ndestroyed.\n\nsock_map_alloc() used to bound its allocation size through\nbpf_map_charge_init(), but the bound was dropped when rlimit-based memory\naccounting was removed.  Reject max_entries > INT_MAX at creation time so\nthe signed iterator in sock_map_free() never sees a value that would\noverflow.\n\nTriggered by syzkaller and reproduced on both a 6.6-based KASAN kernel\nand the upstream v7.3-rc2 kernel."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"f4a73f49e256bd835368504462be3b57b03febff","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"c56191af3a578b9cc265fa3bd5fc0752c59c1781","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"909f761868fda329dc69130ef9eb5b5795bcdf00","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"cc70972ddbf0e3398f2f32624d31db78594d50d8","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"cea597519b9ca6d691c98d92460ead8ece2a07af","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"ba7d627dbc67d62df2fa66d7b41e743c3ace0ec8","versionType":"git"},{"version":"0d2c4f9640501ff57ba0be1f5644a02c29a02fa1","status":"affected","lessThan":"814a81c842bd88f6bd8a4ce550d560df071a5d03","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock_map.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/sock_map.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f4a73f49e256bd835368504462be3b57b03febff"},{"url":"https://git.kernel.org/stable/c/c56191af3a578b9cc265fa3bd5fc0752c59c1781"},{"url":"https://git.kernel.org/stable/c/909f761868fda329dc69130ef9eb5b5795bcdf00"},{"url":"https://git.kernel.org/stable/c/cc70972ddbf0e3398f2f32624d31db78594d50d8"},{"url":"https://git.kernel.org/stable/c/cea597519b9ca6d691c98d92460ead8ece2a07af"},{"url":"https://git.kernel.org/stable/c/ba7d627dbc67d62df2fa66d7b41e743c3ace0ec8"},{"url":"https://git.kernel.org/stable/c/814a81c842bd88f6bd8a4ce550d560df071a5d03"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:22:13.833Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.18.55"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"7.2.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}