{"id":"CVE-2026-74734","state":"PUBLISHED","title":"firewire: ohci: fix NULL pointer dereference in ar_context_release","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfirewire: ohci: fix NULL pointer dereference in ar_context_release\n\nDuring the error handling path of the driver's probe function, a NULL\npointer dereference can occur in ar_context_release().\n\nWhen pci_probe() fails early (e.g., if pcim_enable_device() or MMIO mapping\nfails), the devres cleanup mechanism invokes release_ohci(). This function\nunconditionally calls ar_context_release() to clean up the asynchronous\nreceive contexts. However, if ar_context_init() was not yet called,\nctx->ohci remains NULL (as the fw_ohci structure is zero-initialized by\ndevres_alloc()).\n\nar_context_release() immediately dereferences ctx->ohci to get the dev\npointer before checking if the context was actually initialized, leading to\na crash:\n\nOops: general protection fault, probably for non-canonical address\n0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI\nKASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\nRIP: 0010:ar_context_release+0x3f/0x380 drivers/firewire/ohci.c:543\nCall Trace:\n release_ohci+0x3f/0x60 drivers/firewire/ohci.c:3567\n release_nodes drivers/base/devres.c:546 [inline]\n devres_release_all+0x1a8/0x260 drivers/base/devres.c:576\n device_unbind_cleanup drivers/base/dd.c:597 [inline]\n really_probe+0x451/0xae0 drivers/base/dd.c:772\n\nTo fix this, move the assignment of the dev pointer after the !ctx->buffer\ncheck. If ctx->buffer is NULL, it indicates that the context was never\nsuccessfully initialized and there is nothing to release, safely avoiding\nthe dereference of the uninitialized ctx->ohci pointer.","publishedAt":"2026-08-26T14:36:48.753Z","updatedAt":"2026-10-21T12:46:20.638Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"3770a4794a14331c8ca6a674e49c021827521c2c","versionType":"git"},{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"ca2fa74f3200ced6e0a940753ad99844c42ad7c8","versionType":"git"},{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"ed5470771c7ed7f959230c4697f316af83426a90","versionType":"git"},{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"7d228ba43279de2d191f25e139fad166409c2c06","versionType":"git"},{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"42d217add8d80d6e7d9f58f80d11ea9b07ea113e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firewire/ohci.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.5","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.46","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.10","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firewire/ohci.c"]}],"references":["https://git.kernel.org/stable/c/3770a4794a14331c8ca6a674e49c021827521c2c","https://git.kernel.org/stable/c/ca2fa74f3200ced6e0a940753ad99844c42ad7c8","https://git.kernel.org/stable/c/ed5470771c7ed7f959230c4697f316af83426a90","https://git.kernel.org/stable/c/7d228ba43279de2d191f25e139fad166409c2c06","https://git.kernel.org/stable/c/42d217add8d80d6e7d9f58f80d11ea9b07ea113e"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74734.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74734","state":"PUBLISHED","datePublished":"2026-08-26T14:36:48.753Z","dateUpdated":"2026-10-21T12:46:20.638Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.930Z"},"containers":{"cna":{"title":"firewire: ohci: fix NULL pointer dereference in ar_context_release","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfirewire: ohci: fix NULL pointer dereference in ar_context_release\n\nDuring the error handling path of the driver's probe function, a NULL\npointer dereference can occur in ar_context_release().\n\nWhen pci_probe() fails early (e.g., if pcim_enable_device() or MMIO mapping\nfails), the devres cleanup mechanism invokes release_ohci(). This function\nunconditionally calls ar_context_release() to clean up the asynchronous\nreceive contexts. However, if ar_context_init() was not yet called,\nctx->ohci remains NULL (as the fw_ohci structure is zero-initialized by\ndevres_alloc()).\n\nar_context_release() immediately dereferences ctx->ohci to get the dev\npointer before checking if the context was actually initialized, leading to\na crash:\n\nOops: general protection fault, probably for non-canonical address\n0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI\nKASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\nRIP: 0010:ar_context_release+0x3f/0x380 drivers/firewire/ohci.c:543\nCall Trace:\n release_ohci+0x3f/0x60 drivers/firewire/ohci.c:3567\n release_nodes drivers/base/devres.c:546 [inline]\n devres_release_all+0x1a8/0x260 drivers/base/devres.c:576\n device_unbind_cleanup drivers/base/dd.c:597 [inline]\n really_probe+0x451/0xae0 drivers/base/dd.c:772\n\nTo fix this, move the assignment of the dev pointer after the !ctx->buffer\ncheck. If ctx->buffer is NULL, it indicates that the context was never\nsuccessfully initialized and there is nothing to release, safely avoiding\nthe dereference of the uninitialized ctx->ohci pointer."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"3770a4794a14331c8ca6a674e49c021827521c2c","versionType":"git"},{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"ca2fa74f3200ced6e0a940753ad99844c42ad7c8","versionType":"git"},{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"ed5470771c7ed7f959230c4697f316af83426a90","versionType":"git"},{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"7d228ba43279de2d191f25e139fad166409c2c06","versionType":"git"},{"version":"5716e58aecdd4f7225c2e46ce903a839fc54f22f","status":"affected","lessThan":"42d217add8d80d6e7d9f58f80d11ea9b07ea113e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firewire/ohci.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.5","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.46","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.10","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/firewire/ohci.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3770a4794a14331c8ca6a674e49c021827521c2c"},{"url":"https://git.kernel.org/stable/c/ca2fa74f3200ced6e0a940753ad99844c42ad7c8"},{"url":"https://git.kernel.org/stable/c/ed5470771c7ed7f959230c4697f316af83426a90"},{"url":"https://git.kernel.org/stable/c/7d228ba43279de2d191f25e139fad166409c2c06"},{"url":"https://git.kernel.org/stable/c/42d217add8d80d6e7d9f58f80d11ea9b07ea113e"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:46:20.638Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.18.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.1.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}