{"id":"CVE-2026-45904","state":"PUBLISHED","title":"powerpc/eeh: fix recursive pci_lock_rescan_remove locking in EEH event handling","description":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/eeh: fix recursive pci_lock_rescan_remove locking in EEH event handling\n\nThe recent commit 1010b4c012b0 (\"powerpc/eeh: Make EEH driver device\nhotplug safe\") restructured the EEH driver to improve synchronization\nwith the PCI hotplug layer.\n\nHowever, it inadvertently moved pci_lock_rescan_remove() outside its\nintended scope in eeh_handle_normal_event(), leading to broken PCI\nerror reporting and improper EEH event triggering. Specifically,\neeh_handle_normal_event() acquired pci_lock_rescan_remove() before\ncalling eeh_pe_bus_get(), but eeh_pe_bus_get() itself attempts to\nacquire the same lock internally, causing nested locking and disrupting\nnormal EEH event handling paths.\n\nThis patch adds a boolean parameter do_lock to _eeh_pe_bus_get(),\nwith two public wrappers:\n    eeh_pe_bus_get() with locking enabled.\n    eeh_pe_bus_get_nolock() that skips locking.\n\nCallers that already hold pci_lock_rescan_remove() now use\neeh_pe_bus_get_nolock() to avoid recursive lock acquisition.\n\nAdditionally, pci_lock_rescan_remove() calls are restored to the correct\nposition—after eeh_pe_bus_get() and immediately before iterating affected\nPEs and devices. This ensures EEH-triggered PCI removes occur under proper\nbus rescan locking without recursive lock contention.\n\nThe eeh_pe_loc_get() function has been split into two functions:\n    eeh_pe_loc_get(struct eeh_pe *pe) which retrieves the loc for given PE.\n    eeh_pe_loc_get_bus(struct pci_bus *bus) which retrieves the location\n    code for given bus.\n\nThis resolves lockdep warnings such as:\n<snip>\n[   84.964298] [    T928] ============================================\n[   84.964304] [    T928] WARNING: possible recursive locking detected\n[   84.964311] [    T928] 6.18.0-rc3 #51 Not tainted\n[   84.964315] [    T928] --------------------------------------------\n[   84.964320] [    T928] eehd/928 is trying to acquire lock:\n[   84.964324] [    T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40\n[   84.964342] [    T928]\n                       but task is already holding lock:\n[   84.964347] [    T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40\n[   84.964357] [    T928]\n                       other info that might help us debug this:\n[   84.964363] [    T928]  Possible unsafe locking scenario:\n\n[   84.964367] [    T928]        CPU0\n[   84.964370] [    T928]        ----\n[   84.964373] [    T928]   lock(pci_rescan_remove_lock);\n[   84.964378] [    T928]   lock(pci_rescan_remove_lock);\n[   84.964383] [    T928]\n                       *** DEADLOCK ***\n\n[   84.964388] [    T928]  May be due to missing lock nesting notation\n\n[   84.964393] [    T928] 1 lock held by eehd/928:\n[   84.964397] [    T928]  #0: c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40\n[   84.964408] [    T928]\n                       stack backtrace:\n[   84.964414] [    T928] CPU: 2 UID: 0 PID: 928 Comm: eehd Not tainted 6.18.0-rc3 #51 VOLUNTARY\n[   84.964417] [    T928] Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_022) hv:phyp pSeries\n[   84.964419] [    T928] Call Trace:\n[   84.964420] [    T928] [c0000011a7157990] [c000000001705de4] dump_stack_lvl+0xc8/0x130 (unreliable)\n[   84.964424] [    T928] [c0000011a71579d0] [c0000000002f66e0] print_deadlock_bug+0x430/0x440\n[   84.964428] [    T928] [c0000011a7157a70] [c0000000002fd0c0] __lock_acquire+0x1530/0x2d80\n[   84.964431] [    T928] [c0000011a7157ba0] [c0000000002fea54] lock_acquire+0x144/0x410\n[   84.964433] [    T928] [c0000011a7157cb0] [c0000011a7157cb0] __mutex_lock+0xf4/0x1050\n[   84.964436] [    T928] [c0000011a7157e00] [c000000000de21d8] pci_lock_rescan_remove+0x28/0x40\n[   84.964439] [    T928] [c0000011a7157e20] [c00000000004ed98] eeh_pe_bus_get+0x48/0xc0\n[   84.964442] [    T928] [c0000011a7157e50] [c00000\n---truncated---","publishedAt":"2026-05-27T12:17:12.504Z","updatedAt":"2026-05-27T12:17:12.504Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"502f08831a9afb72dc98a56ae6504da43e93b250","status":"affected","lessThan":"89810e2d80281d42f855fac813786758ee16e323","versionType":"git"},{"version":"f56e004b781719d8fdf6c9619b15caf2579bc1f2","status":"affected","lessThan":"788dd28fd49610d6047cbb15dbf1186afffdfbaf","versionType":"git"},{"version":"59c6d3d81d42bf543c90597b4f38c53d6874c5a1","status":"affected","lessThan":"f49faa4a64f8ac0e38983e606075b25dfcfc9ad4","versionType":"git"},{"version":"a426e8a6ae161f51888585b065db0f8f93ab2e16","status":"affected","lessThan":"87a1f93986aa1500b85aeff16b0b71c29ea116ea","versionType":"git"},{"version":"d2c60a8a387e9fcc28447ef36c03f8e49fd052a6","status":"affected","lessThan":"f8b16d5764ee1e78c1ef333017ad383ffe76fcdc","versionType":"git"},{"version":"1010b4c012b0d78dfb9d3132b49aa2ef024a07a7","status":"affected","lessThan":"6e6561231c6cfc32c5631aeecc0928ff2b14265c","versionType":"git"},{"version":"1010b4c012b0d78dfb9d3132b49aa2ef024a07a7","status":"affected","lessThan":"b85ee287bfe52c6b2d9b41758b5e0d08679d5b39","versionType":"git"},{"version":"1010b4c012b0d78dfb9d3132b49aa2ef024a07a7","status":"affected","lessThan":"815a8d2feb5615ae7f0b5befd206af0b0160614c","versionType":"git"},{"version":"d42bbd8f30ac38b1ce54715bf08ec3dac18d6b25","status":"affected","versionType":"git"},{"version":"19d5036e7ad766cf212aebec23b9f1d7924a62bc","status":"affected","versionType":"git"},{"version":"5.10.241","status":"affected","lessThan":"5.10.252","versionType":"semver"},{"version":"5.15.190","status":"affected","lessThan":"5.15.202","versionType":"semver"},{"version":"6.1.148","status":"affected","lessThan":"6.1.165","versionType":"semver"},{"version":"6.6.102","status":"affected","lessThan":"6.6.128","versionType":"semver"},{"version":"6.12.42","status":"affected","lessThan":"6.12.75","versionType":"semver"},{"version":"6.15.10","status":"affected","lessThan":"6.16","versionType":"semver"},{"version":"6.16.1","status":"affected","lessThan":"6.17","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/powerpc/include/asm/eeh.h","arch/powerpc/kernel/eeh_driver.c","arch/powerpc/kernel/eeh_pe.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","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":["arch/powerpc/include/asm/eeh.h","arch/powerpc/kernel/eeh_driver.c","arch/powerpc/kernel/eeh_pe.c"]}],"references":["https://git.kernel.org/stable/c/89810e2d80281d42f855fac813786758ee16e323","https://git.kernel.org/stable/c/788dd28fd49610d6047cbb15dbf1186afffdfbaf","https://git.kernel.org/stable/c/f49faa4a64f8ac0e38983e606075b25dfcfc9ad4","https://git.kernel.org/stable/c/87a1f93986aa1500b85aeff16b0b71c29ea116ea","https://git.kernel.org/stable/c/f8b16d5764ee1e78c1ef333017ad383ffe76fcdc","https://git.kernel.org/stable/c/6e6561231c6cfc32c5631aeecc0928ff2b14265c","https://git.kernel.org/stable/c/b85ee287bfe52c6b2d9b41758b5e0d08679d5b39","https://git.kernel.org/stable/c/815a8d2feb5615ae7f0b5befd206af0b0160614c"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45904.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45904","state":"PUBLISHED","datePublished":"2026-05-27T12:17:12.504Z","dateUpdated":"2026-05-27T12:17:12.504Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.084Z"},"containers":{"cna":{"title":"powerpc/eeh: fix recursive pci_lock_rescan_remove locking in EEH event handling","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/eeh: fix recursive pci_lock_rescan_remove locking in EEH event handling\n\nThe recent commit 1010b4c012b0 (\"powerpc/eeh: Make EEH driver device\nhotplug safe\") restructured the EEH driver to improve synchronization\nwith the PCI hotplug layer.\n\nHowever, it inadvertently moved pci_lock_rescan_remove() outside its\nintended scope in eeh_handle_normal_event(), leading to broken PCI\nerror reporting and improper EEH event triggering. Specifically,\neeh_handle_normal_event() acquired pci_lock_rescan_remove() before\ncalling eeh_pe_bus_get(), but eeh_pe_bus_get() itself attempts to\nacquire the same lock internally, causing nested locking and disrupting\nnormal EEH event handling paths.\n\nThis patch adds a boolean parameter do_lock to _eeh_pe_bus_get(),\nwith two public wrappers:\n    eeh_pe_bus_get() with locking enabled.\n    eeh_pe_bus_get_nolock() that skips locking.\n\nCallers that already hold pci_lock_rescan_remove() now use\neeh_pe_bus_get_nolock() to avoid recursive lock acquisition.\n\nAdditionally, pci_lock_rescan_remove() calls are restored to the correct\nposition—after eeh_pe_bus_get() and immediately before iterating affected\nPEs and devices. This ensures EEH-triggered PCI removes occur under proper\nbus rescan locking without recursive lock contention.\n\nThe eeh_pe_loc_get() function has been split into two functions:\n    eeh_pe_loc_get(struct eeh_pe *pe) which retrieves the loc for given PE.\n    eeh_pe_loc_get_bus(struct pci_bus *bus) which retrieves the location\n    code for given bus.\n\nThis resolves lockdep warnings such as:\n<snip>\n[   84.964298] [    T928] ============================================\n[   84.964304] [    T928] WARNING: possible recursive locking detected\n[   84.964311] [    T928] 6.18.0-rc3 #51 Not tainted\n[   84.964315] [    T928] --------------------------------------------\n[   84.964320] [    T928] eehd/928 is trying to acquire lock:\n[   84.964324] [    T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40\n[   84.964342] [    T928]\n                       but task is already holding lock:\n[   84.964347] [    T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40\n[   84.964357] [    T928]\n                       other info that might help us debug this:\n[   84.964363] [    T928]  Possible unsafe locking scenario:\n\n[   84.964367] [    T928]        CPU0\n[   84.964370] [    T928]        ----\n[   84.964373] [    T928]   lock(pci_rescan_remove_lock);\n[   84.964378] [    T928]   lock(pci_rescan_remove_lock);\n[   84.964383] [    T928]\n                       *** DEADLOCK ***\n\n[   84.964388] [    T928]  May be due to missing lock nesting notation\n\n[   84.964393] [    T928] 1 lock held by eehd/928:\n[   84.964397] [    T928]  #0: c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40\n[   84.964408] [    T928]\n                       stack backtrace:\n[   84.964414] [    T928] CPU: 2 UID: 0 PID: 928 Comm: eehd Not tainted 6.18.0-rc3 #51 VOLUNTARY\n[   84.964417] [    T928] Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_022) hv:phyp pSeries\n[   84.964419] [    T928] Call Trace:\n[   84.964420] [    T928] [c0000011a7157990] [c000000001705de4] dump_stack_lvl+0xc8/0x130 (unreliable)\n[   84.964424] [    T928] [c0000011a71579d0] [c0000000002f66e0] print_deadlock_bug+0x430/0x440\n[   84.964428] [    T928] [c0000011a7157a70] [c0000000002fd0c0] __lock_acquire+0x1530/0x2d80\n[   84.964431] [    T928] [c0000011a7157ba0] [c0000000002fea54] lock_acquire+0x144/0x410\n[   84.964433] [    T928] [c0000011a7157cb0] [c0000011a7157cb0] __mutex_lock+0xf4/0x1050\n[   84.964436] [    T928] [c0000011a7157e00] [c000000000de21d8] pci_lock_rescan_remove+0x28/0x40\n[   84.964439] [    T928] [c0000011a7157e20] [c00000000004ed98] eeh_pe_bus_get+0x48/0xc0\n[   84.964442] [    T928] [c0000011a7157e50] [c00000\n---truncated---"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"502f08831a9afb72dc98a56ae6504da43e93b250","status":"affected","lessThan":"89810e2d80281d42f855fac813786758ee16e323","versionType":"git"},{"version":"f56e004b781719d8fdf6c9619b15caf2579bc1f2","status":"affected","lessThan":"788dd28fd49610d6047cbb15dbf1186afffdfbaf","versionType":"git"},{"version":"59c6d3d81d42bf543c90597b4f38c53d6874c5a1","status":"affected","lessThan":"f49faa4a64f8ac0e38983e606075b25dfcfc9ad4","versionType":"git"},{"version":"a426e8a6ae161f51888585b065db0f8f93ab2e16","status":"affected","lessThan":"87a1f93986aa1500b85aeff16b0b71c29ea116ea","versionType":"git"},{"version":"d2c60a8a387e9fcc28447ef36c03f8e49fd052a6","status":"affected","lessThan":"f8b16d5764ee1e78c1ef333017ad383ffe76fcdc","versionType":"git"},{"version":"1010b4c012b0d78dfb9d3132b49aa2ef024a07a7","status":"affected","lessThan":"6e6561231c6cfc32c5631aeecc0928ff2b14265c","versionType":"git"},{"version":"1010b4c012b0d78dfb9d3132b49aa2ef024a07a7","status":"affected","lessThan":"b85ee287bfe52c6b2d9b41758b5e0d08679d5b39","versionType":"git"},{"version":"1010b4c012b0d78dfb9d3132b49aa2ef024a07a7","status":"affected","lessThan":"815a8d2feb5615ae7f0b5befd206af0b0160614c","versionType":"git"},{"version":"d42bbd8f30ac38b1ce54715bf08ec3dac18d6b25","status":"affected","versionType":"git"},{"version":"19d5036e7ad766cf212aebec23b9f1d7924a62bc","status":"affected","versionType":"git"},{"version":"5.10.241","status":"affected","lessThan":"5.10.252","versionType":"semver"},{"version":"5.15.190","status":"affected","lessThan":"5.15.202","versionType":"semver"},{"version":"6.1.148","status":"affected","lessThan":"6.1.165","versionType":"semver"},{"version":"6.6.102","status":"affected","lessThan":"6.6.128","versionType":"semver"},{"version":"6.12.42","status":"affected","lessThan":"6.12.75","versionType":"semver"},{"version":"6.15.10","status":"affected","lessThan":"6.16","versionType":"semver"},{"version":"6.16.1","status":"affected","lessThan":"6.17","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/powerpc/include/asm/eeh.h","arch/powerpc/kernel/eeh_driver.c","arch/powerpc/kernel/eeh_pe.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"5.10.252","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.202","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.165","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.128","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.14","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.4","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":["arch/powerpc/include/asm/eeh.h","arch/powerpc/kernel/eeh_driver.c","arch/powerpc/kernel/eeh_pe.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/89810e2d80281d42f855fac813786758ee16e323"},{"url":"https://git.kernel.org/stable/c/788dd28fd49610d6047cbb15dbf1186afffdfbaf"},{"url":"https://git.kernel.org/stable/c/f49faa4a64f8ac0e38983e606075b25dfcfc9ad4"},{"url":"https://git.kernel.org/stable/c/87a1f93986aa1500b85aeff16b0b71c29ea116ea"},{"url":"https://git.kernel.org/stable/c/f8b16d5764ee1e78c1ef333017ad383ffe76fcdc"},{"url":"https://git.kernel.org/stable/c/6e6561231c6cfc32c5631aeecc0928ff2b14265c"},{"url":"https://git.kernel.org/stable/c/b85ee287bfe52c6b2d9b41758b5e0d08679d5b39"},{"url":"https://git.kernel.org/stable/c/815a8d2feb5615ae7f0b5befd206af0b0160614c"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-27T12:17:12.504Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.241","versionEndExcluding":"5.10.252"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.190","versionEndExcluding":"5.15.202"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.148","versionEndExcluding":"6.1.165"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.102","versionEndExcluding":"6.6.128"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.42","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.18.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.19.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"7.0"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}