From: Kees Cook <kees@kernel.org> stable inclusion from stable-v5.10.241 commit a732502bf3bbe859613b6d7b2b0313b11f0474ac category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/9098 CVE: CVE-2025-38676 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 8503d0fcb1086a7cfe26df67ca4bd9bd9e99bdec ] While the kernel command line is considered trusted in most environments, avoid writing 1 byte past the end of "acpiid" if the "str" argument is maximum length. Reported-by: Simcha Kosman <simcha.kosman@cyberark.com> Closes: https://lore.kernel.org/all/AS8P193MB2271C4B24BCEDA31830F37AE84A52@AS8P193MB... Fixes: b6b26d86c61c ("iommu/amd: Add a length limitation for the ivrs_acpihid command-line parameter") Signed-off-by: Kees Cook <kees@kernel.org> Reviewed-by: Ankit Soni <Ankit.Soni@amd.com> Link: https://lore.kernel.org/r/20250804154023.work.970-kees@kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com> --- drivers/iommu/amd/init.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index d0a4ec42fd12..8e3570b77798 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -3223,7 +3223,7 @@ static int __init parse_ivrs_acpihid(char *str) { u32 seg = 0, bus, dev, fn; char *hid, *uid, *p, *addr; - char acpiid[ACPIID_LEN] = {0}; + char acpiid[ACPIID_LEN + 1] = { }; /* size with NULL terminator */ int i; addr = strchr(str, '@'); @@ -3249,7 +3249,7 @@ static int __init parse_ivrs_acpihid(char *str) /* We have the '@', make it the terminator to get just the acpiid */ *addr++ = 0; - if (strlen(str) > ACPIID_LEN + 1) + if (strlen(str) > ACPIID_LEN) goto not_found; if (sscanf(str, "=%s", acpiid) != 1) -- 2.22.0