On Mon, Sep 28, 2026 at 05:40:11PM +0000, Priyank Rathod wrote: > When firmware reports PCIe Advanced Error Reporting (AER) events via ACPI > APEI GHES (ghes_handle_aer()), it allocates a snapshot buffer from > ghes_estatus_pool to store the aer_capability_regs registers before > enqueuing the error record into aer_recover_ring. > > aer_recover_queue() returns void, so ghes_handle_aer() cannot release that > buffer itself; ownership is handed to the AER code, which until now freed > it only on the fully successful path. If the record cannot be enqueued, or > if a dequeued record cannot be mapped to a pci_dev, the allocation is > silently leaked. Under a sustained error storm this exhausts > ghes_estatus_pool, which then breaks GHES hardware error reporting > system-wide. > > This series fixes both leak paths and documents the ownership rule: > > Patch 1: aer_recover_queue() when kfifo_in_spinlocked() fails because > aer_recover_ring (capacity 16) is full. The rejected entry is > freed immediately via ghes_estatus_pool_region_free(). > > Patch 2: aer_recover_work_func() when a dequeued entry cannot be mapped to > an active PCI device (pdev is NULL). The loop is restructured so > ghes_estatus_pool_region_free() runs unconditionally for every > dequeued item. > > Patch 3: Add a kernel-doc comment stating that aer_recover_queue() takes > ownership of @aer_regs, which must be allocated from > ghes_estatus_pool. This is documentation only, so unlike > patches 1 and 2 it has no Fixes: or Cc: stable tag. > > Signed-off-by: Priyank Rathod <[email protected]>
Applied to pci/aer for v7.4, thanks! > --- > Changes in v5: > - Add patch 3, a kernel-doc comment on aer_recover_queue() stating that > it takes ownership of @aer_regs, which must come from ghes_estatus_pool > (suggested by Kuppuswamy Sathyanarayanan). It is a separate patch so > that the two fixes stay minimal for stable backports, and because the > comment is only accurate once patch 2 is applied. > - Add Kuppuswamy's Reviewed-by to patches 1 and 2. Their code is > unchanged from v4. > - Still applies cleanly to pci/next (94e8d4e94266), before or after > Lukas' "Error reporting for AER-incapable devices" series: > https://lore.kernel.org/r/[email protected] > - Cc Kuppuswamy Sathyanarayanan, Jonathan Cameron, Ilpo Järvinen and > Dave Jiang, plus Shiju Jose and Rafael J. Wysocki as the author and > committer of the commit in Fixes:. > - Link to v4: > https://lore.kernel.org/r/[email protected] > > Changes in v4: > - Rebased onto v7.3-rc3+ (f259f446f519); applies cleanly to pci/next as > well. No conflicts with the Advisory Non-Fatal Error support that landed > in the meantime. > - Added missing Fixes: e2abc47a5a1a ("ACPI: APEI: Fix AER info corruption > when error status data has multiple sections") and Cc: stable to both > patches; that commit (v6.7-rc1) introduced the ghes_estatus_pool > allocation whose ownership these paths drop. > - Patch 1: use braces on both arms of the if/else and fix the continuation > alignment (checkpatch --strict). > - Both patches now build warning-free with W=1 and CONFIG_ACPI_APEI_PCIEAER=y > (earlier revisions were only build-tested with APEI disabled, which > compiles neither of the modified functions). > - Explained in both commit messages why the caller cannot free the buffer, > and when the missing-pci_dev path is reachable. > - Cc: Lukas Wunner, who has been active in this code. > - Link to v3: > https://lore.kernel.org/r/[email protected] > > Changes in v3: > - Resent to fix threading of the series. > - Link to v2: > https://lore.kernel.org/r/[email protected] > > Changes in v2: > - Refactored aer_recover_work_func() to ensure ghes_estatus_pool_region_free() > is called unconditionally for every dequeued record. > - Added Patch 1 to fix related memory leak in aer_recover_queue() on kfifo > buffer overflow. > - Link to v1: > https://lore.kernel.org/r/[email protected] > > --- > Priyank Rathod (3): > PCI/AER: Fix memory leak in aer_recover_queue() on kfifo buffer overflow > PCI/AER: Fix memory leak in aer_recover_work_func() when pci_dev is > missing > PCI/AER: Document that aer_recover_queue() takes ownership of aer_regs > > drivers/pci/pcie/aer.c | 48 +++++++++++++++++++++++++++++++++++------------- > 1 file changed, 35 insertions(+), 13 deletions(-) > --- > base-commit: f259f446f5198d98e13756d2cd531812a0ad3064 > change-id: 20260803-b4-fix-aer-memleaks-524a1bd5e888 > > Best regards, > -- > Priyank Rathod <[email protected]> >
