UPSTREAM: ARM: 8731/1: Fix csum_partial_copy_from_user() stack mismatch

An additional 'ip' will be pushed to the stack, for restoring the DACR later, if CONFIG_CPU_SW_DOMAIN_PAN defined. However, the fixup still get the err_ptr by add ivanmeler#8*4 to sp, which results in the fact that the code area pointed by the LR will be overwritten, or the kernel will crash if CONFIG_DEBUG_RODATA is enabled. This patch fixes the stack mismatch. Fixes: a5e090acbf54 ("ARM: software-based priviledged-no-access support") Signed-off-by: Lvqiang Huang <[email protected]> Signed-off-by: Chunyan Zhang <[email protected]> Signed-off-by: Russell King <[email protected]> (cherry picked from commit 36b0cb84ee858f02c256d26f0cb4229c78e3399e) Signed-off-by: Greg Kroah-Hartman <[email protected]> Change-Id: I056565608b846352ef7ab725764db5a1e4067533
fcuzzocrea · May 30, 2021 · 0f978ad · 0f978ad
1 parent 2bc17df
commit 0f978ad
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/arch/arm/lib/csumpartialcopyuser.S b/arch/arm/lib/csumpartialcopyuser.S
@@ -85,7 +85,11 @@
 		.pushsection .fixup,"ax"
 		.align	4
 9001:		mov	r4, #-EFAULT
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+		ldr	r5, [sp, #9*4]		@ *err_ptr
+#else
 		ldr	r5, [sp, #8*4]		@ *err_ptr
+#endif
 		str	r4, [r5]
 		ldmia	sp, {r1, r2}		@ retrieve dst, len
 		add	r2, r2, r1