From f9bc28aedfb5bbd572d2d365f3095c1becd7209b Mon Sep 17 00:00:00 2001 From: Sam Bobroff Date: Wed, 12 Sep 2018 11:23:20 +1000 Subject: [PATCH] powerpc/eeh: Fix possible null deref in eeh_dump_dev_log() If an error occurs during an unplug operation, it's possible for eeh_dump_dev_log() to be called when edev->pdn is null, which currently leads to dereferencing a null pointer. Handle this by skipping the error log for those devices. Signed-off-by: Sam Bobroff Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/eeh.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index 6ebba3e48b01..c72767a5327a 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -169,6 +169,11 @@ static size_t eeh_dump_dev_log(struct eeh_dev *edev, char *buf, size_t len) int n = 0, l = 0; char buffer[128]; + if (!pdn) { + pr_warn("EEH: Note: No error log for absent device.\n"); + return 0; + } + n += scnprintf(buf+n, len-n, "%04x:%02x:%02x.%01x\n", pdn->phb->global_number, pdn->busno, PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));