This is a note to let you know that I've just added the patch titled powerpc/rtas: Validate rtas.entry before calling enter_rtas() to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-rtas-validate-rtas.entry-before-calling-enter_rtas.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 8832317f662c06f5c06e638f57bfe89a71c9b266 Mon Sep 17 00:00:00 2001 From: Vasant Hegde <hegdevasant@xxxxxxxxxxxxxxxxxx> Date: Fri, 16 Oct 2015 15:53:29 +0530 Subject: powerpc/rtas: Validate rtas.entry before calling enter_rtas() From: Vasant Hegde <hegdevasant@xxxxxxxxxxxxxxxxxx> commit 8832317f662c06f5c06e638f57bfe89a71c9b266 upstream. Currently we do not validate rtas.entry before calling enter_rtas(). This leads to a kernel oops when user space calls rtas system call on a powernv platform (see below). This patch adds code to validate rtas.entry before making enter_rtas() call. Oops: Exception in kernel mode, sig: 4 [#1] SMP NR_CPUS=1024 NUMA PowerNV task: c000000004294b80 ti: c0000007e1a78000 task.ti: c0000007e1a78000 NIP: 0000000000000000 LR: 0000000000009c14 CTR: c000000000423140 REGS: c0000007e1a7b920 TRAP: 0e40 Not tainted (3.18.17-340.el7_1.pkvm3_1_0.2400.1.ppc64le) MSR: 1000000000081000 <HV,ME> CR: 00000000 XER: 00000000 CFAR: c000000000009c0c SOFTE: 0 NIP [0000000000000000] (null) LR [0000000000009c14] 0x9c14 Call Trace: [c0000007e1a7bba0] [c00000000041a7f4] avc_has_perm_noaudit+0x54/0x110 (unreliable) [c0000007e1a7bd80] [c00000000002ddc0] ppc_rtas+0x150/0x2d0 [c0000007e1a7be30] [c000000000009358] syscall_exit+0x0/0x98 Fixes: 55190f88789a ("powerpc: Add skeleton PowerNV platform") Reported-by: NAGESWARA R. SASTRY <nasastry@xxxxxxxxxx> Signed-off-by: Vasant Hegde <hegdevasant@xxxxxxxxxxxxxxxxxx> [mpe: Reword change log, trim oops, and add stable + fixes] Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/kernel/rtas.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -1041,6 +1041,9 @@ asmlinkage int ppc_rtas(struct rtas_args if (!capable(CAP_SYS_ADMIN)) return -EPERM; + if (!rtas.entry) + return -EINVAL; + if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0) return -EFAULT; Patches currently in stable-queue which might be from hegdevasant@xxxxxxxxxxxxxxxxxx are queue-4.1/powerpc-rtas-validate-rtas.entry-before-calling-enter_rtas.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html