Date: Tue, 7 Jan 2025 15:35:25 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 6ba2c036a011 - main - pci_find_cap_method(): limit number of iterations for finding a capability Message-ID: <202501071535.507FZPJv029064@gitrepo.freebsd.org>
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The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=6ba2c036a0117ac02f9979b7dc49f15e9c1ea9c9 commit 6ba2c036a0117ac02f9979b7dc49f15e9c1ea9c9 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2025-01-06 23:29:18 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2025-01-07 15:34:59 +0000 pci_find_cap_method(): limit number of iterations for finding a capability Powered down device might return 0xff of extended config registers reads, causing loop. PR: 283815 Reviewed by: imp Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D48348 --- sys/dev/pci/pci.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c index cf01115581e1..0b02d873c5a1 100644 --- a/sys/dev/pci/pci.c +++ b/sys/dev/pci/pci.c @@ -1519,6 +1519,7 @@ pci_find_cap_method(device_t dev, device_t child, int capability, pcicfgregs *cfg = &dinfo->cfg; uint32_t status; uint8_t ptr; + int cnt; /* * Check the CAP_LIST bit of the PCI status register first. @@ -1545,9 +1546,11 @@ pci_find_cap_method(device_t dev, device_t child, int capability, ptr = pci_read_config(child, ptr, 1); /* - * Traverse the capabilities list. + * Traverse the capabilities list. Limit by total theoretical + * maximum number of caps: capability needs at least id and + * next registers, and any type X header cannot contain caps. */ - while (ptr != 0) { + for (cnt = 0; ptr != 0 && cnt < (PCIE_REGMAX - 0x40) / 2; cnt++) { if (pci_read_config(child, ptr + PCICAP_ID, 1) == capability) { if (capreg != NULL) *capreg = ptr;
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