{"id":"CVE-2026-23438","state":"PUBLISHED","title":"net: mvpp2: guard flow control update with global_tx_fc in buffer switching","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mvpp2: guard flow control update with global_tx_fc in buffer switching\n\nmvpp2_bm_switch_buffers() unconditionally calls\nmvpp2_bm_pool_update_priv_fc() when switching between per-cpu and\nshared buffer pool modes. This function programs CM3 flow control\nregisters via mvpp2_cm3_read()/mvpp2_cm3_write(), which dereference\npriv->cm3_base without any NULL check.\n\nWhen the CM3 SRAM resource is not present in the device tree (the\nthird reg entry added by commit 60523583b07c (\"dts: marvell: add CM3\nSRAM memory to cp11x ethernet device tree\")), priv->cm3_base remains\nNULL and priv->global_tx_fc is false. Any operation that triggers\nmvpp2_bm_switch_buffers(), for example an MTU change that crosses\nthe jumbo frame threshold, will crash:\n\n  Unable to handle kernel NULL pointer dereference at\n  virtual address 0000000000000000\n  Mem abort info:\n    ESR = 0x0000000096000006\n    EC = 0x25: DABT (current EL), IL = 32 bits\n  pc : readl+0x0/0x18\n  lr : mvpp2_cm3_read.isra.0+0x14/0x20\n  Call trace:\n   readl+0x0/0x18\n   mvpp2_bm_pool_update_fc+0x40/0x12c\n   mvpp2_bm_pool_update_priv_fc+0x94/0xd8\n   mvpp2_bm_switch_buffers.isra.0+0x80/0x1c0\n   mvpp2_change_mtu+0x140/0x380\n   __dev_set_mtu+0x1c/0x38\n   dev_set_mtu_ext+0x78/0x118\n   dev_set_mtu+0x48/0xa8\n   dev_ifsioc+0x21c/0x43c\n   dev_ioctl+0x2d8/0x42c\n   sock_ioctl+0x314/0x378\n\nEvery other flow control call site in the driver already guards\nhardware access with either priv->global_tx_fc or port->tx_fc.\nmvpp2_bm_switch_buffers() is the only place that omits this check.\n\nAdd the missing priv->global_tx_fc guard to both the disable and\nre-enable calls in mvpp2_bm_switch_buffers(), consistent with the\nrest of the driver.","publishedAt":"2026-04-03T15:15:22.701Z","updatedAt":"2026-10-15T01:14:58.956Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"0cfcd31f98fc608dc9406bff3fee3a9dd364d014","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"da089f74a993f846685067b14158cb41b879ff29","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"ff0c54f088f7ab91dbbf47cf8244460f99122750","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"7bd20f4b3ef3044dc55acd5b8ef748a70d29d03f","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"7df2b50cae1a76cbb90b294f3edb61e3e10bf2e9","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"8baced53a35fc9710f80d6ca016a2c418dc3231f","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"8a63baadf08453f66eb582fdb6dd234f72024723","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.12","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.20","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.10","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c"]}],"references":["https://git.kernel.org/stable/c/0cfcd31f98fc608dc9406bff3fee3a9dd364d014","https://git.kernel.org/stable/c/da089f74a993f846685067b14158cb41b879ff29","https://git.kernel.org/stable/c/ff0c54f088f7ab91dbbf47cf8244460f99122750","https://git.kernel.org/stable/c/7bd20f4b3ef3044dc55acd5b8ef748a70d29d03f","https://git.kernel.org/stable/c/7df2b50cae1a76cbb90b294f3edb61e3e10bf2e9","https://git.kernel.org/stable/c/8baced53a35fc9710f80d6ca016a2c418dc3231f","https://git.kernel.org/stable/c/8a63baadf08453f66eb582fdb6dd234f72024723","https://cert-portal.siemens.com/productcert/html/ssa-082556.html","https://cert-portal.siemens.com/productcert/html/ssa-019113.html","https://cert-portal.siemens.com/productcert/html/ssa-457936.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/23xxx/CVE-2026-23438.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23438","state":"PUBLISHED","datePublished":"2026-04-03T15:15:22.701Z","dateUpdated":"2026-10-15T01:14:58.956Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-01-13T15:37:46.017Z"},"containers":{"cna":{"title":"net: mvpp2: guard flow control update with global_tx_fc in buffer switching","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mvpp2: guard flow control update with global_tx_fc in buffer switching\n\nmvpp2_bm_switch_buffers() unconditionally calls\nmvpp2_bm_pool_update_priv_fc() when switching between per-cpu and\nshared buffer pool modes. This function programs CM3 flow control\nregisters via mvpp2_cm3_read()/mvpp2_cm3_write(), which dereference\npriv->cm3_base without any NULL check.\n\nWhen the CM3 SRAM resource is not present in the device tree (the\nthird reg entry added by commit 60523583b07c (\"dts: marvell: add CM3\nSRAM memory to cp11x ethernet device tree\")), priv->cm3_base remains\nNULL and priv->global_tx_fc is false. Any operation that triggers\nmvpp2_bm_switch_buffers(), for example an MTU change that crosses\nthe jumbo frame threshold, will crash:\n\n  Unable to handle kernel NULL pointer dereference at\n  virtual address 0000000000000000\n  Mem abort info:\n    ESR = 0x0000000096000006\n    EC = 0x25: DABT (current EL), IL = 32 bits\n  pc : readl+0x0/0x18\n  lr : mvpp2_cm3_read.isra.0+0x14/0x20\n  Call trace:\n   readl+0x0/0x18\n   mvpp2_bm_pool_update_fc+0x40/0x12c\n   mvpp2_bm_pool_update_priv_fc+0x94/0xd8\n   mvpp2_bm_switch_buffers.isra.0+0x80/0x1c0\n   mvpp2_change_mtu+0x140/0x380\n   __dev_set_mtu+0x1c/0x38\n   dev_set_mtu_ext+0x78/0x118\n   dev_set_mtu+0x48/0xa8\n   dev_ifsioc+0x21c/0x43c\n   dev_ioctl+0x2d8/0x42c\n   sock_ioctl+0x314/0x378\n\nEvery other flow control call site in the driver already guards\nhardware access with either priv->global_tx_fc or port->tx_fc.\nmvpp2_bm_switch_buffers() is the only place that omits this check.\n\nAdd the missing priv->global_tx_fc guard to both the disable and\nre-enable calls in mvpp2_bm_switch_buffers(), consistent with the\nrest of the driver."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"0cfcd31f98fc608dc9406bff3fee3a9dd364d014","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"da089f74a993f846685067b14158cb41b879ff29","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"ff0c54f088f7ab91dbbf47cf8244460f99122750","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"7bd20f4b3ef3044dc55acd5b8ef748a70d29d03f","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"7df2b50cae1a76cbb90b294f3edb61e3e10bf2e9","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"8baced53a35fc9710f80d6ca016a2c418dc3231f","versionType":"git"},{"version":"3a616b92a9d17448d96a33bf58e69f01457fd43a","status":"affected","lessThan":"8a63baadf08453f66eb582fdb6dd234f72024723","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.12","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.20","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.10","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0cfcd31f98fc608dc9406bff3fee3a9dd364d014"},{"url":"https://git.kernel.org/stable/c/da089f74a993f846685067b14158cb41b879ff29"},{"url":"https://git.kernel.org/stable/c/ff0c54f088f7ab91dbbf47cf8244460f99122750"},{"url":"https://git.kernel.org/stable/c/7bd20f4b3ef3044dc55acd5b8ef748a70d29d03f"},{"url":"https://git.kernel.org/stable/c/7df2b50cae1a76cbb90b294f3edb61e3e10bf2e9"},{"url":"https://git.kernel.org/stable/c/8baced53a35fc9710f80d6ca016a2c418dc3231f"},{"url":"https://git.kernel.org/stable/c/8a63baadf08453f66eb582fdb6dd234f72024723"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T22:06:54.590Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.1.167"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.6.130"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.12.78"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.18.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.19.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.5","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.5","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.5","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.5","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.5","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:14:58.956Z"},"x_adpType":"supplier"}]}}}