{"id":"CVE-2026-31728","state":"PUBLISHED","title":"usb: gadget: u_ether: Fix race between gether_disconnect and eth_stop","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: u_ether: Fix race between gether_disconnect and eth_stop\n\nA race condition between gether_disconnect() and eth_stop() leads to a\nNULL pointer dereference. Specifically, if eth_stop() is triggered\nconcurrently while gether_disconnect() is tearing down the endpoints,\neth_stop() attempts to access the cleared endpoint descriptor, causing\nthe following NPE:\n\n  Unable to handle kernel NULL pointer dereference\n  Call trace:\n   __dwc3_gadget_ep_enable+0x60/0x788\n   dwc3_gadget_ep_enable+0x70/0xe4\n   usb_ep_enable+0x60/0x15c\n   eth_stop+0xb8/0x108\n\nBecause eth_stop() crashes while holding the dev->lock, the thread\nrunning gether_disconnect() fails to acquire the same lock and spins\nforever, resulting in a hardlockup:\n\n  Core - Debugging Information for Hardlockup core(7)\n  Call trace:\n   queued_spin_lock_slowpath+0x94/0x488\n   _raw_spin_lock+0x64/0x6c\n   gether_disconnect+0x19c/0x1e8\n   ncm_set_alt+0x68/0x1a0\n   composite_setup+0x6a0/0xc50\n\nThe root cause is that the clearing of dev->port_usb in\ngether_disconnect() is delayed until the end of the function.\n\nMove the clearing of dev->port_usb to the very beginning of\ngether_disconnect() while holding dev->lock. This cuts off the link\nimmediately, ensuring eth_stop() will see dev->port_usb as NULL and\nsafely bail out.","publishedAt":"2026-05-01T14:14:28.231Z","updatedAt":"2026-05-11T22:14:36.858Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"f02980594deef751e42133714aee25228f1494c6","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"e1e7a66584bf0aff3becb73c19fa31527889fc9e","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"a259ba0bce3b192c04334499690372a250f7d0b1","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"f6813c2b2ae78def76b69e0f9d72f80e4a1c4aca","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"bbb09bb89ffa571475f66daca9482b974cd29d6a","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"6ad77458637b78ec655e3da5f112c862e6690a9d","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"8ff689edfeceb5e3ec1623e09af2b2aa0f1098a8","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"e1eabb072c75681f78312c484ccfffb7430f206e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/u_ether.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.27","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.27","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.169","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.134","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","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/usb/gadget/function/u_ether.c"]}],"references":["https://git.kernel.org/stable/c/f02980594deef751e42133714aee25228f1494c6","https://git.kernel.org/stable/c/e1e7a66584bf0aff3becb73c19fa31527889fc9e","https://git.kernel.org/stable/c/a259ba0bce3b192c04334499690372a250f7d0b1","https://git.kernel.org/stable/c/f6813c2b2ae78def76b69e0f9d72f80e4a1c4aca","https://git.kernel.org/stable/c/bbb09bb89ffa571475f66daca9482b974cd29d6a","https://git.kernel.org/stable/c/6ad77458637b78ec655e3da5f112c862e6690a9d","https://git.kernel.org/stable/c/8ff689edfeceb5e3ec1623e09af2b2aa0f1098a8","https://git.kernel.org/stable/c/e1eabb072c75681f78312c484ccfffb7430f206e"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31728.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31728","state":"PUBLISHED","datePublished":"2026-05-01T14:14:28.231Z","dateUpdated":"2026-05-11T22:14:36.858Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.134Z"},"containers":{"cna":{"title":"usb: gadget: u_ether: Fix race between gether_disconnect and eth_stop","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: u_ether: Fix race between gether_disconnect and eth_stop\n\nA race condition between gether_disconnect() and eth_stop() leads to a\nNULL pointer dereference. Specifically, if eth_stop() is triggered\nconcurrently while gether_disconnect() is tearing down the endpoints,\neth_stop() attempts to access the cleared endpoint descriptor, causing\nthe following NPE:\n\n  Unable to handle kernel NULL pointer dereference\n  Call trace:\n   __dwc3_gadget_ep_enable+0x60/0x788\n   dwc3_gadget_ep_enable+0x70/0xe4\n   usb_ep_enable+0x60/0x15c\n   eth_stop+0xb8/0x108\n\nBecause eth_stop() crashes while holding the dev->lock, the thread\nrunning gether_disconnect() fails to acquire the same lock and spins\nforever, resulting in a hardlockup:\n\n  Core - Debugging Information for Hardlockup core(7)\n  Call trace:\n   queued_spin_lock_slowpath+0x94/0x488\n   _raw_spin_lock+0x64/0x6c\n   gether_disconnect+0x19c/0x1e8\n   ncm_set_alt+0x68/0x1a0\n   composite_setup+0x6a0/0xc50\n\nThe root cause is that the clearing of dev->port_usb in\ngether_disconnect() is delayed until the end of the function.\n\nMove the clearing of dev->port_usb to the very beginning of\ngether_disconnect() while holding dev->lock. This cuts off the link\nimmediately, ensuring eth_stop() will see dev->port_usb as NULL and\nsafely bail out."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"f02980594deef751e42133714aee25228f1494c6","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"e1e7a66584bf0aff3becb73c19fa31527889fc9e","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"a259ba0bce3b192c04334499690372a250f7d0b1","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"f6813c2b2ae78def76b69e0f9d72f80e4a1c4aca","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"bbb09bb89ffa571475f66daca9482b974cd29d6a","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"6ad77458637b78ec655e3da5f112c862e6690a9d","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"8ff689edfeceb5e3ec1623e09af2b2aa0f1098a8","versionType":"git"},{"version":"2b3d942c4878084a37991a65e66512c02b8fa2ad","status":"affected","lessThan":"e1eabb072c75681f78312c484ccfffb7430f206e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/u_ether.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.27","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.27","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.169","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.134","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","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/usb/gadget/function/u_ether.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f02980594deef751e42133714aee25228f1494c6"},{"url":"https://git.kernel.org/stable/c/e1e7a66584bf0aff3becb73c19fa31527889fc9e"},{"url":"https://git.kernel.org/stable/c/a259ba0bce3b192c04334499690372a250f7d0b1"},{"url":"https://git.kernel.org/stable/c/f6813c2b2ae78def76b69e0f9d72f80e4a1c4aca"},{"url":"https://git.kernel.org/stable/c/bbb09bb89ffa571475f66daca9482b974cd29d6a"},{"url":"https://git.kernel.org/stable/c/6ad77458637b78ec655e3da5f112c862e6690a9d"},{"url":"https://git.kernel.org/stable/c/8ff689edfeceb5e3ec1623e09af2b2aa0f1098a8"},{"url":"https://git.kernel.org/stable/c/e1eabb072c75681f78312c484ccfffb7430f206e"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T22:14:36.858Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"5.10.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.1.169"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.6.134"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.12.81"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.27","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}