Messages in this thread Patch in this message | | | Date | Wed, 12 Dec 2007 15:47:59 -0500 | From | Jeff Dike <> | Subject | [PATCH 4/6] UML - Don't allow processes to call into stub |
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Kill a process that tries to branch into a stub and execute a system call. There are no security implications here - a system call in a stub is treated the same as a system call anywhere else. But if a process is trying to branch into a stub, either it is trying something nasty or it has gone haywire, so it's a good idea to get rid of it in either case.
Signed-off-by: Jeff Dike <jdike@linux.intel.com> --- arch/um/os-Linux/skas/process.c | 3 +++ 1 file changed, 3 insertions(+)
Index: linux-2.6.22/arch/um/os-Linux/skas/process.c =================================================================== --- linux-2.6.22.orig/arch/um/os-Linux/skas/process.c 2007-12-05 12:51:53.000000000 -0500 +++ linux-2.6.22/arch/um/os-Linux/skas/process.c 2007-12-05 16:34:55.000000000 -0500 @@ -146,6 +146,9 @@ static void handle_trap(int pid, struct { int err, status; + if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END)) + fatal_sigsegv(); + /* Mark this as a syscall */ UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->gp);
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