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x86/insn-eval: Make 0 a valid RIP for insn_get_effective_ip()

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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
This commit is contained in:
Joerg Roedel 2021-05-19 15:52:49 +02:00 committed by Borislav Petkov
parent 4aca2d99fd
commit f2df15639e
1 changed files with 7 additions and 7 deletions
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14
arch/x86/lib/insn-eval.c
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@ -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);