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authorNikita Zhandarovich <n.zhandarovich@fintech.ru>2023-03-06 08:06:56 -0800
committerBorislav Petkov (AMD) <bp@alien8.de>2023-03-16 12:22:25 +0100
commitcbebd68f59f03633469f3ecf9bea99cd6cce3854 (patch)
tree6529f1fae07f4989614f7db143bc379580b0f579
parent0424a7dfe9129b93f29b277511a60e87f052ac6b (diff)
x86/mm: Fix use of uninitialized buffer in sme_enable()
cmdline_find_option() may fail before doing any initialization of the buffer array. This may lead to unpredictable results when the same buffer is used later in calls to strncmp() function. Fix the issue by returning early if cmdline_find_option() returns an error. Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE. Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption") Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/20230306160656.14844-1-n.zhandarovich@fintech.ru
-rw-r--r--arch/x86/mm/mem_encrypt_identity.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index 88cccd65029d..c6efcf559d88 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -600,7 +600,8 @@ void __init sme_enable(struct boot_params *bp)
cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr |
((u64)bp->ext_cmd_line_ptr << 32));
- cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer));
+ if (cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer)) < 0)
+ return;
if (!strncmp(buffer, cmdline_on, sizeof(buffer)))
sme_me_mask = me_mask;