[PATCH] sys_pselect7 vs compat_sys_pselect7 uaccess error handling
758333458a
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>
This commit is contained in:
parent
7870db4c7f
commit
87c2b7c045
1 changed files with 17 additions and 3 deletions
20
fs/compat.c
20
fs/compat.c
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@ -1835,9 +1835,12 @@ asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp,
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} while (!ret && !timeout && tsp && (ts.tv_sec || ts.tv_nsec));
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} while (!ret && !timeout && tsp && (ts.tv_sec || ts.tv_nsec));
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if (ret == 0 && tsp && !(current->personality & STICKY_TIMEOUTS)) {
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if (tsp) {
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struct compat_timespec rts;
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struct compat_timespec rts;
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if (current->personality & STICKY_TIMEOUTS)
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goto sticky;
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rts.tv_sec = timeout / HZ;
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rts.tv_sec = timeout / HZ;
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rts.tv_nsec = (timeout % HZ) * (NSEC_PER_SEC/HZ);
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rts.tv_nsec = (timeout % HZ) * (NSEC_PER_SEC/HZ);
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if (rts.tv_nsec >= NSEC_PER_SEC) {
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if (rts.tv_nsec >= NSEC_PER_SEC) {
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@ -1846,8 +1849,19 @@ asmlinkage long compat_sys_pselect7(int n, compat_ulong_t __user *inp,
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}
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}
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if (compat_timespec_compare(&rts, &ts) >= 0)
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if (compat_timespec_compare(&rts, &ts) >= 0)
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rts = ts;
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rts = ts;
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if (copy_to_user(tsp, &rts, sizeof(rts)))
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if (copy_to_user(tsp, &rts, sizeof(rts))) {
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ret = -EFAULT;
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sticky:
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/*
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* If an application puts its timeval in read-only
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* memory, we don't want the Linux-specific update to
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* the timeval to cause a fault after the select has
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* completed successfully. However, because we're not
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* updating the timeval, we can't restart the system
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* call.
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*/
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if (ret == -ERESTARTNOHAND)
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ret = -EINTR;
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}
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}
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}
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if (ret == -ERESTARTNOHAND) {
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if (ret == -ERESTARTNOHAND) {
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