From c3f37faa71f5d26dd2144b3f2b14525ec8f5e41f Mon Sep 17 00:00:00 2001 From: Pavel Paklov Date: Tue, 25 Mar 2025 09:22:44 +0000 Subject: [PATCH] iommu/amd: Fix potential buffer overflow in parse_ivrs_acpihid commit 8dee308e4c01dea48fc104d37f92d5b58c50b96c upstream. There is a string parsing logic error which can lead to an overflow of hid or uid buffers. Comparing ACPIID_LEN against a total string length doesn't take into account the lengths of individual hid and uid buffers so the check is insufficient in some cases. For example if the length of hid string is 4 and the length of the uid string is 260, the length of str will be equal to ACPIID_LEN + 1 but uid string will overflow uid buffer which size is 256. The same applies to the hid string with length 13 and uid string with length 250. Check the length of hid and uid strings separately to prevent buffer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: ca3bf5d47cec ("iommu/amd: Introduces ivrs_acpihid kernel parameter") Cc: stable@vger.kernel.org Signed-off-by: Pavel Paklov Link: https://lore.kernel.org/r/20250325092259.392844-1-Pavel.Paklov@cyberprotect.ru Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/amd/init.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index c9598c506ff94..bc78e86655516 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -3610,6 +3610,14 @@ found: while (*uid == '0' && *(uid + 1)) uid++; + if (strlen(hid) >= ACPIHID_HID_LEN) { + pr_err("Invalid command line: hid is too long\n"); + return 1; + } else if (strlen(uid) >= ACPIHID_UID_LEN) { + pr_err("Invalid command line: uid is too long\n"); + return 1; + } + i = early_acpihid_map_size++; memcpy(early_acpihid_map[i].hid, hid, strlen(hid)); memcpy(early_acpihid_map[i].uid, uid, strlen(uid)); -- 2.47.3