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| author | Peter Maydell | 2016-07-18 16:35:59 +0200 |
|---|---|---|
| committer | Riku Voipio | 2016-09-21 13:25:26 +0200 |
| commit | 2ba7fae3bd688f5bb6cb08defc731d77e6bd943c (patch) | |
| tree | a2138d834c2f9d056db7c55b26118b554865be46 /linux-user/syscall.c | |
| parent | linux-user: Use direct syscall for utimensat (diff) | |
| download | qemu-2ba7fae3bd688f5bb6cb08defc731d77e6bd943c.tar.gz qemu-2ba7fae3bd688f5bb6cb08defc731d77e6bd943c.tar.xz qemu-2ba7fae3bd688f5bb6cb08defc731d77e6bd943c.zip | |
linux-user: Check for bad event numbers in epoll_wait
The kernel checks that the maxevents parameter to epoll_wait
is non-negative and not larger than EP_MAX_EVENTS. Add this
check to our implementation, so that:
* we fail these cases EINVAL rather than EFAULT
* we don't pass negative or overflowing values to the
lock_user() size calculation
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.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 21ae996dd1..eecccbb25c 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -11501,6 +11501,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, int maxevents = arg3; int timeout = arg4; + if (maxevents <= 0 || maxevents > TARGET_EP_MAX_EVENTS) { + ret = -TARGET_EINVAL; + break; + } + target_ep = lock_user(VERIFY_WRITE, arg2, maxevents * sizeof(struct target_epoll_event), 1); if (!target_ep) { |