Commit 56b88a3b authored by Richard Weinberger's avatar Richard Weinberger
Browse files

um: Fix kernel mode fault condition 



We have to exclude memory locations <= PAGE_SIZE from
the condition and let the kernel mode fault path catch it.
Otherwise a kernel NULL pointer exception will be reported
as a kernel user space access.

Fixes: d2313084 (um: Catch unprotected user memory access)
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 6b187337

arch/um/kernel/trap.c

+1 −1
Original line number Diff line number Diff line
@@ -220,7 +220,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, 
		show_regs(container_of(regs, struct pt_regs, regs));

		panic("Segfault with no mm");

	}

	else if (!is_user && address < TASK_SIZE) {

	else if (!is_user && address > PAGE_SIZE && address < TASK_SIZE) {

		show_regs(container_of(regs, struct pt_regs, regs));

		panic("Kernel tried to access user memory at addr 0x%lx, ip 0x%lx",

		       address, ip);