[PATCH v4 7/8] arm64: Forbid calling compat sigreturn from 64-bit tasks
From: Amanieu d'Antras <hidden>
Date: 2021-04-30 20:38:29
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
It's impossible for this syscall to do anything sensible in this context. Signed-off-by: Amanieu d'Antras <redacted> Co-developed-by: Ryan Houdek <redacted> Signed-off-by: Ryan Houdek <redacted> --- arch/arm64/kernel/signal32.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
index 2f507f565c48..e2bdd1eaefd8 100644
--- a/arch/arm64/kernel/signal32.c
+++ b/arch/arm64/kernel/signal32.c@@ -237,6 +237,10 @@ COMPAT_SYSCALL_DEFINE0(sigreturn) /* Always make any pending restarted system calls return -EINTR */ current->restart_block.fn = do_no_restart_syscall; + /* Reject attempts to call this from a 64-bit process. */ + if (!is_compat_task()) + goto badframe; + /* * Since we stacked the signal on a 64-bit boundary, * then 'sp' should be word aligned here. If it's
@@ -268,6 +272,10 @@ COMPAT_SYSCALL_DEFINE0(rt_sigreturn) /* Always make any pending restarted system calls return -EINTR */ current->restart_block.fn = do_no_restart_syscall; + /* Reject attempts to call this from a 64-bit process. */ + if (!is_compat_task()) + goto badframe; + /* * Since we stacked the signal on a 64-bit boundary, * then 'sp' should be word aligned here. If it's
--
2.31.1
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