{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-63988", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.025Z", "datePublished": "2026-07-19T14:56:09.677Z", "dateUpdated": "2026-07-19T14:56:09.677Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-19T14:56:09.677Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbridge: Fix sleep in atomic context in sysfs path\n\nSince the start of the git history, brport_store() always acquired the\nbridge lock. Back then this decision made sense: The bridge lock\nprotects the STP state of the bridge and its ports and at that time the\nfunction was only used by two STP related attributes (cost and\npriority).\n\nNowadays, brport_store() processes a lot more attributes and most of\nthem do not need the bridge lock:\n\n* Bridge flags: Only require RTNL. Read locklessly by the data path.\n Annotations can be added in net-next.\n\n* FDB port flushing: Only requires the FDB lock.\n\n* Multicast attributes: Only require the multicast lock.\n\n* Group forward mask: Only requires RTNL. Read locklessly by the data\n path. Annotations can be added in net-next.\n\n* Backup port: Only requires RTNL. Read locklessly by the data path.\n\nThis is a problem as the bridge calls dev_set_promiscuity() when certain\nbridge port flags change and this function can sleep since the commit\ncited below, resulting in a splat such as [1].\n\nFix this by reducing the scope of the bridge lock and only take it when\nprocessing the two STP related attributes that require it. Remove the\nnow stale comment from br_switchdev_set_port_flag(). The\nSWITCHDEV_F_DEFER flag can be removed in net-next.\n\n[1]\nBUG: sleeping function called from invalid context at net/core/dev_addr_lists.c:1262\nin_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 372, name: bash\npreempt_count: 201, expected: 0\nRCU nest depth: 0, expected: 0\n5 locks held by bash/372:\n#0: ffff88810c51c3f0 (sb_writers#7){.+.+}-{0:0}, at: ksys_write (fs/read_write.c:740)\n#1: ffff888115ce9480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter (fs/kernfs/file.c:343)\n#2: ffff88810b9fd330 (kn->active#37){.+.+}-{0:0}, at: kernfs_fop_write_iter (fs/kernfs/file.c:80 fs/kernfs/file.c:344)\n#3: ffffffffa59473a0 (rtnl_mutex){+.+.}-{4:4}, at: brport_store (net/bridge/br_sysfs_if.c:326)\n#4: ffff8881099d2d58 (&br->lock){+...}-{3:3}, at: brport_store (./include/linux/spinlock.h:348 net/bridge/br_sysfs_if.c:345)\nPreemption disabled at:\n 0x0\nHardware name: Bochs Bochs, BIOS Bochs 01/01/2011\nCall Trace:\n\ndump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)\n__might_resched.cold (kernel/sched/core.c:9163)\nnetif_rx_mode_run (net/core/dev_addr_lists.c:1262)\nnetif_rx_mode_sync (net/core/dev_addr_lists.c:1428)\ndev_set_promiscuity (net/core/dev_api.c:289)\nbr_manage_promisc (net/bridge/br_if.c:135 net/bridge/br_if.c:172)\nbr_port_flags_change (net/bridge/br_if.c:242 net/bridge/br_if.c:747)\nstore_learning (net/bridge/br_sysfs_if.c:79 net/bridge/br_sysfs_if.c:235)\nbrport_store (net/bridge/br_sysfs_if.c:346)\nkernfs_fop_write_iter (fs/kernfs/file.c:352)\nnew_sync_write (fs/read_write.c:595)\nvfs_write (fs/read_write.c:688)\nksys_write (fs/read_write.c:740)\ndo_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)\nentry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bridge/br_switchdev.c", "net/bridge/br_sysfs_if.c" ], "versions": [ { "version": "78cd408356fe3edbac66598772fd347bf3e32c1f", "lessThan": "e976e3f2f2005c6267089a1a3b6344f234a59a55", "status": "affected", "versionType": "git" }, { "version": "78cd408356fe3edbac66598772fd347bf3e32c1f", "lessThan": "2f9cb30d97e45686f3119fff3b30f12259950910", "status": "affected", "versionType": "git" }, { "version": "78cd408356fe3edbac66598772fd347bf3e32c1f", "lessThan": "6d34594cc619d0d4b07d5afcad8b5984f3526dcf", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bridge/br_switchdev.c", "net/bridge/br_sysfs_if.c" ], "versions": [ { "version": "6.15", "status": "affected" }, { "version": "0", "lessThan": "6.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.35", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.12", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "6.18.35" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.0.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e976e3f2f2005c6267089a1a3b6344f234a59a55" }, { "url": "https://git.kernel.org/stable/c/2f9cb30d97e45686f3119fff3b30f12259950910" }, { "url": "https://git.kernel.org/stable/c/6d34594cc619d0d4b07d5afcad8b5984f3526dcf" } ], "title": "bridge: Fix sleep in atomic context in sysfs path", "x_generator": { "engine": "bippy-1.2.0" } } } }