5.15-stable review patch. If anyone has any objections, please let me know.
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From: Kees Cook kees@kernel.org
[ 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 --- 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 b6ee83b81d32..065d626d5905 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -3286,7 +3286,7 @@ 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, '@'); @@ -3312,7 +3312,7 @@ 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)