[PATCH] sys_pselect7 vs compat_sys_pselect7 uaccess error handling (87c2b7c0) · Commits · 戴 / test

fixes the not checked copy_to_user return value of compat_sys_pselect7. I ran into this too because of an old source tree, but my fix would look quite a bit different to Andi's fix. The reason is that the compat function IMHO should behave the very same as the non-compat function if possible. Since sys_pselect7 does not return -EFAULT in this specific case, change the compat code so it behaves like sys_pselect7. Cc: David Woodhouse <dwmw2@infradead.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by:

Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

fs/compat.c

+17 −3

Original line number	Diff line number	Diff line
		@@ -1835,9 +1835,12 @@ asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp,

		} while (!ret && !timeout && tsp && (ts.tv_sec \|\| ts.tv_nsec));

		if (ret == 0 && tsp && !(current->personality & STICKY_TIMEOUTS)) {
		if (tsp) {
		struct compat_timespec rts;

		if (current->personality & STICKY_TIMEOUTS)
		goto sticky;

		rts.tv_sec = timeout / HZ;
		rts.tv_nsec = (timeout % HZ) * (NSEC_PER_SEC/HZ);
		if (rts.tv_nsec >= NSEC_PER_SEC) {
		@@ -1846,8 +1849,19 @@ asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp,
		}
		if (compat_timespec_compare(&rts, &ts) >= 0)
		rts = ts;
		if (copy_to_user(tsp, &rts, sizeof(rts)))
		ret = -EFAULT;
		if (copy_to_user(tsp, &rts, sizeof(rts))) {
		sticky:
		/*
		* If an application puts its timeval in read-only
		* memory, we don't want the Linux-specific update to
		* the timeval to cause a fault after the select has
		* completed successfully. However, because we're not
		* updating the timeval, we can't restart the system
		* call.
		*/
		if (ret == -ERESTARTNOHAND)
		ret = -EINTR;
		}
		}

		if (ret == -ERESTARTNOHAND) {

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