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authorMark Brown <broonie@kernel.org>2023-01-31 22:20:45 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2023-02-01 17:56:47 +0000
commitad678be4238720384fa9e21b9b08b5540ac7ca5d (patch)
tree319e20450d92a32f65c2fd7f3579ebe30bad6995 /arch
parent24d68345a02aee155b22deb26fde3e08332d8f88 (diff)
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arm64/signal: Only read new data when parsing the ZT context
When we parse the ZT signal context we read the entire context from userspace, including the generic signal context header which was already read by parse_user_sigframe() and padding bytes that we ignore. Avoid the possibility of relying on the second read of the data read twice by only reading the data which we are actually going to use. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20221212-arm64-signal-cleanup-v3-7-4545c94b20ff@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/kernel/signal.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 7810d090c025..d7b5ed8a9b7f 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -521,7 +521,7 @@ static int preserve_zt_context(struct zt_context __user *ctx)
static int restore_zt_context(struct user_ctxs *user)
{
int err;
- struct zt_context zt;
+ u16 nregs;
/* ZA must be restored first for this check to be valid */
if (!thread_za_enabled(&current->thread))
@@ -530,10 +530,10 @@ static int restore_zt_context(struct user_ctxs *user)
if (user->zt_size != ZT_SIG_CONTEXT_SIZE(1))
return -EINVAL;
- if (__copy_from_user(&zt, user->zt, sizeof(zt)))
+ if (__copy_from_user(&nregs, &(user->zt->nregs), sizeof(nregs)))
return -EFAULT;
- if (zt.nregs != 1)
+ if (nregs != 1)
return -EINVAL;
/*