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authorPeter Maydell <peter.maydell@linaro.org>2016-07-18 16:30:36 +0100
committerRiku Voipio <riku.voipio@linaro.org>2016-09-21 14:25:53 +0300
commitce9c139d93db03e464341385976606b7568b768f (patch)
treef948812bc2eac2e2da2258b94a0461e0970059ea /linux-user/syscall.c
parent2ba7fae3bd688f5bb6cb08defc731d77e6bd943c (diff)
downloadfocaccia-qemu-ce9c139d93db03e464341385976606b7568b768f.tar.gz
focaccia-qemu-ce9c139d93db03e464341385976606b7568b768f.zip
linux-user: Range check the nfds argument to ppoll syscall
Do an initial range check on the ppoll syscall's nfds argument,
to avoid possible overflow in the calculation of the lock_user()
size argument. The host kernel will later apply the rather lower
limit based on RLIMIT_NOFILE as appropriate.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Diffstat (limited to 'linux-user/syscall.c')
-rw-r--r--linux-user/syscall.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index eecccbb25c..7a50a57d4b 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -9661,6 +9661,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             pfd = NULL;
             target_pfd = NULL;
             if (nfds) {
+                if (nfds > (INT_MAX / sizeof(struct target_pollfd))) {
+                    ret = -TARGET_EINVAL;
+                    break;
+                }
+
                 target_pfd = lock_user(VERIFY_WRITE, arg1,
                                        sizeof(struct target_pollfd) * nfds, 1);
                 if (!target_pfd) {