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authorJoerg Roedel <jroedel@suse.de>2021-05-19 15:52:49 +0200
committerBorislav Petkov <bp@suse.de>2021-06-15 11:24:21 +0200
commitf2df15639e44d23bf82a86a03092472c7278cd39 (patch)
tree247da372fd19beae98f68d3331954f8761df8955 /arch/x86/lib
parent4aca2d99fd27698cf82d55aed4859fde859082ac (diff)
x86/insn-eval: Make 0 a valid RIP for insn_get_effective_ip()
In theory, 0 is a valid value for the instruction pointer so don't use it as the error return value from insn_get_effective_ip(). Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210614135327.9921-5-joro@8bytes.org
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/insn-eval.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c
index a67afd74232c..4eecb9c7c6a0 100644
--- a/arch/x86/lib/insn-eval.c
+++ b/arch/x86/lib/insn-eval.c
@@ -1417,7 +1417,7 @@ void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs)
}
}
-static unsigned long insn_get_effective_ip(struct pt_regs *regs)
+static int insn_get_effective_ip(struct pt_regs *regs, unsigned long *ip)
{
unsigned long seg_base = 0;
@@ -1430,10 +1430,12 @@ static unsigned long insn_get_effective_ip(struct pt_regs *regs)
if (!user_64bit_mode(regs)) {
seg_base = insn_get_seg_base(regs, INAT_SEG_REG_CS);
if (seg_base == -1L)
- return 0;
+ return -EINVAL;
}
- return seg_base + regs->ip;
+ *ip = seg_base + regs->ip;
+
+ return 0;
}
/**
@@ -1455,8 +1457,7 @@ int insn_fetch_from_user(struct pt_regs *regs, unsigned char buf[MAX_INSN_SIZE])
unsigned long ip;
int not_copied;
- ip = insn_get_effective_ip(regs);
- if (!ip)
+ if (insn_get_effective_ip(regs, &ip))
return 0;
not_copied = copy_from_user(buf, (void __user *)ip, MAX_INSN_SIZE);
@@ -1484,8 +1485,7 @@ int insn_fetch_from_user_inatomic(struct pt_regs *regs, unsigned char buf[MAX_IN
unsigned long ip;
int not_copied;
- ip = insn_get_effective_ip(regs);
- if (!ip)
+ if (insn_get_effective_ip(regs, &ip))
return 0;
not_copied = __copy_from_user_inatomic(buf, (void __user *)ip, MAX_INSN_SIZE);