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From:   Tom Lendacky <thomas.lendacky@amd.com>
To:     <linux-kernel@vger.kernel.org>, <x86@kernel.org>
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        Dionna Glaze <dionnaglaze@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v9 1/6] x86/sev: Fix calculation of end address based on number of pages
Date:   Tue, 6 Jun 2023 09:51:22 -0500
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When calculating an end address based on an unsigned int number of pages,
any value greater than or equal to 0x100000 that is shift PAGE_SHIFT bits
results in a 0 value, resulting in an invalid end address. Change the
number of pages variable in various routines from an unsigned int to an
unsigned long to calculate the end address correctly.

Fixes: 5e5ccff60a29 ("x86/sev: Add helper for validating pages in early enc attribute changes")
Fixes: dc3f3d2474b8 ("x86/mm: Validate memory when changing the C-bit")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 arch/x86/include/asm/sev.h | 16 ++++++++--------
 arch/x86/kernel/sev.c      | 14 +++++++-------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 13dc2a9d23c1..7ca5c9ec8b52 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -192,12 +192,12 @@ struct snp_guest_request_ioctl;
 
 void setup_ghcb(void);
 void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
-					 unsigned int npages);
+					 unsigned long npages);
 void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
-					unsigned int npages);
+					unsigned long npages);
 void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op);
-void snp_set_memory_shared(unsigned long vaddr, unsigned int npages);
-void snp_set_memory_private(unsigned long vaddr, unsigned int npages);
+void snp_set_memory_shared(unsigned long vaddr, unsigned long npages);
+void snp_set_memory_private(unsigned long vaddr, unsigned long npages);
 void snp_set_wakeup_secondary_cpu(void);
 bool snp_init(struct boot_params *bp);
 void __init __noreturn snp_abort(void);
@@ -212,12 +212,12 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
 static inline void setup_ghcb(void) { }
 static inline void __init
-early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
+early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
 static inline void __init
-early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
+early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
 static inline void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) { }
-static inline void snp_set_memory_shared(unsigned long vaddr, unsigned int npages) { }
-static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npages) { }
+static inline void snp_set_memory_shared(unsigned long vaddr, unsigned long npages) { }
+static inline void snp_set_memory_private(unsigned long vaddr, unsigned long npages) { }
 static inline void snp_set_wakeup_secondary_cpu(void) { }
 static inline bool snp_init(struct boot_params *bp) { return false; }
 static inline void snp_abort(void) { }
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index b031244d6d2d..108bbae59c35 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -645,7 +645,7 @@ static u64 __init get_jump_table_addr(void)
 	return ret;
 }
 
-static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool validate)
+static void pvalidate_pages(unsigned long vaddr, unsigned long npages, bool validate)
 {
 	unsigned long vaddr_end;
 	int rc;
@@ -662,7 +662,7 @@ static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool valid
 	}
 }
 
-static void __init early_set_pages_state(unsigned long paddr, unsigned int npages, enum psc_op op)
+static void __init early_set_pages_state(unsigned long paddr, unsigned long npages, enum psc_op op)
 {
 	unsigned long paddr_end;
 	u64 val;
@@ -701,7 +701,7 @@ static void __init early_set_pages_state(unsigned long paddr, unsigned int npage
 }
 
 void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
-					 unsigned int npages)
+					 unsigned long npages)
 {
 	/*
 	 * This can be invoked in early boot while running identity mapped, so
@@ -723,7 +723,7 @@ void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long padd
 }
 
 void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
-					unsigned int npages)
+					unsigned long npages)
 {
 	/*
 	 * This can be invoked in early boot while running identity mapped, so
@@ -879,7 +879,7 @@ static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
 		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
 }
 
-static void set_pages_state(unsigned long vaddr, unsigned int npages, int op)
+static void set_pages_state(unsigned long vaddr, unsigned long npages, int op)
 {
 	unsigned long vaddr_end, next_vaddr;
 	struct snp_psc_desc *desc;
@@ -904,7 +904,7 @@ static void set_pages_state(unsigned long vaddr, unsigned int npages, int op)
 	kfree(desc);
 }
 
-void snp_set_memory_shared(unsigned long vaddr, unsigned int npages)
+void snp_set_memory_shared(unsigned long vaddr, unsigned long npages)
 {
 	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
 		return;
@@ -914,7 +914,7 @@ void snp_set_memory_shared(unsigned long vaddr, unsigned int npages)
 	set_pages_state(vaddr, npages, SNP_PAGE_STATE_SHARED);
 }
 
-void snp_set_memory_private(unsigned long vaddr, unsigned int npages)
+void snp_set_memory_private(unsigned long vaddr, unsigned long npages)
 {
 	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
 		return;
-- 
2.40.1