{"id":"CVE-2026-89718","state":"PUBLISHED","title":"zram: fix out-of-bounds access in writeback_store()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nzram: fix out-of-bounds access in writeback_store()\n\nPatch series \"zram: fix stale scan bounds after reinitialization\".\n\nBoth writeback_store() and read_block_state() derive their table scan\nbounds from zram->disksize before acquiring dev_lock.  If the device is\nreset and reinitialized with a smaller disksize between that read and lock\nacquisition, the bound can describe the old table while the scan operates\non the new one.  This can lead to out-of-bounds slot accesses.\n\nMove both bound calculations under dev_lock so each bound remains\nconsistent with the table throughout its scan.  Keep the fixes separate\nbecause the affected interfaces originate from different commits and can\nbe backported independently.\n\n\nThis patch (of 2):\n\nwriteback_store() calculates the table scan bounds before taking dev_lock.\nA reset followed by reconfiguration with a smaller disksize can therefore\nreplace zram->table while writeback_store() is waiting for the lock.  Once\nit acquires the lock, it sees an initialized device but scans the new\ntable using the old upper bound, resulting in an out-of-bounds access.\n\nCalculate the number of pages while holding dev_lock so the scan bound\nmatches the table protected by the lock.","publishedAt":"2026-09-11T19:46:31.443Z","updatedAt":"2026-10-30T12:32:49.752Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"f1c5611f699a3aa2a85ebd5fec03dc9bc501e6d0","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"c2745e657f0974871fbc60d46d48c2b04e581330","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"4d82d60178b02797dbe529e01ac211b26670c49f","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"ef073edd7cfd31aeb90eeab23273102c601f4d8e","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"07a82a66f8c1894d92e51d97542c32ebf2c51b09","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"894913e2d35c46ff19a77530907771ae57862b96","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/zram/zram_drv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.0","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","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":["drivers/block/zram/zram_drv.c"]}],"references":["https://git.kernel.org/stable/c/f1c5611f699a3aa2a85ebd5fec03dc9bc501e6d0","https://git.kernel.org/stable/c/c2745e657f0974871fbc60d46d48c2b04e581330","https://git.kernel.org/stable/c/4d82d60178b02797dbe529e01ac211b26670c49f","https://git.kernel.org/stable/c/ef073edd7cfd31aeb90eeab23273102c601f4d8e","https://git.kernel.org/stable/c/07a82a66f8c1894d92e51d97542c32ebf2c51b09","https://git.kernel.org/stable/c/894913e2d35c46ff19a77530907771ae57862b96"],"weaknesses":[],"ingestedAt":"2026-10-30T12:52:04.348Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89718.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89718","state":"PUBLISHED","datePublished":"2026-09-11T19:46:31.443Z","dateUpdated":"2026-10-30T12:32:49.752Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.752Z"},"containers":{"cna":{"title":"zram: fix out-of-bounds access in writeback_store()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nzram: fix out-of-bounds access in writeback_store()\n\nPatch series \"zram: fix stale scan bounds after reinitialization\".\n\nBoth writeback_store() and read_block_state() derive their table scan\nbounds from zram->disksize before acquiring dev_lock.  If the device is\nreset and reinitialized with a smaller disksize between that read and lock\nacquisition, the bound can describe the old table while the scan operates\non the new one.  This can lead to out-of-bounds slot accesses.\n\nMove both bound calculations under dev_lock so each bound remains\nconsistent with the table throughout its scan.  Keep the fixes separate\nbecause the affected interfaces originate from different commits and can\nbe backported independently.\n\n\nThis patch (of 2):\n\nwriteback_store() calculates the table scan bounds before taking dev_lock.\nA reset followed by reconfiguration with a smaller disksize can therefore\nreplace zram->table while writeback_store() is waiting for the lock.  Once\nit acquires the lock, it sees an initialized device but scans the new\ntable using the old upper bound, resulting in an out-of-bounds access.\n\nCalculate the number of pages while holding dev_lock so the scan bound\nmatches the table protected by the lock."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"f1c5611f699a3aa2a85ebd5fec03dc9bc501e6d0","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"c2745e657f0974871fbc60d46d48c2b04e581330","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"4d82d60178b02797dbe529e01ac211b26670c49f","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"ef073edd7cfd31aeb90eeab23273102c601f4d8e","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"07a82a66f8c1894d92e51d97542c32ebf2c51b09","versionType":"git"},{"version":"a939888ec38bf1f33e4a903056677e92a4844244","status":"affected","lessThan":"894913e2d35c46ff19a77530907771ae57862b96","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/zram/zram_drv.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.0","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","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":["drivers/block/zram/zram_drv.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f1c5611f699a3aa2a85ebd5fec03dc9bc501e6d0"},{"url":"https://git.kernel.org/stable/c/c2745e657f0974871fbc60d46d48c2b04e581330"},{"url":"https://git.kernel.org/stable/c/4d82d60178b02797dbe529e01ac211b26670c49f"},{"url":"https://git.kernel.org/stable/c/ef073edd7cfd31aeb90eeab23273102c601f4d8e"},{"url":"https://git.kernel.org/stable/c/07a82a66f8c1894d92e51d97542c32ebf2c51b09"},{"url":"https://git.kernel.org/stable/c/894913e2d35c46ff19a77530907771ae57862b96"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:32:49.752Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}