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| author | Dmitry V. Levin <ldv@altlinux.org> | 2017-08-05 23:00:50 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-08-06 21:48:27 +0300 |
| commit | fbb77611e95d3d5b2af86a59754a3130877cb667 (patch) | |
| tree | 026bc121b112736776c5de03463ce52fa4424280 | |
| parent | 0fdd951c9bef93637d5af036851e7a5632fbd6c3 (diff) | |
| download | linux-fbb77611e95d3d5b2af86a59754a3130877cb667.tar.xz | |
Fix compat_sys_sigpending breakage
The latest change of compat_sys_sigpending in commit 8f13621abced
("sigpending(): move compat to native") has broken it in two ways.
First, it tries to write 4 bytes more than userspace expects:
sizeof(old_sigset_t) == sizeof(long) == 8 instead of
sizeof(compat_old_sigset_t) == sizeof(u32) == 4.
Second, on big endian architectures these bytes are being written in the
wrong order.
This bug was found by strace test suite.
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Inspired-by: Eugene Syromyatnikov <evgsyr@gmail.com>
Fixes: 8f13621abced ("sigpending(): move compat to native")
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/signal.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index caed9133ae52..7e33f8c583e6 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3303,12 +3303,15 @@ SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set) #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE1(sigpending, compat_old_sigset_t __user *, set32) { +#ifdef __BIG_ENDIAN sigset_t set; - int err = do_sigpending(&set, sizeof(old_sigset_t)); - if (err == 0) - if (copy_to_user(set32, &set, sizeof(old_sigset_t))) - err = -EFAULT; + int err = do_sigpending(&set, sizeof(set.sig[0])); + if (!err) + err = put_user(set.sig[0], set32); return err; +#else + return sys_rt_sigpending((sigset_t __user *)set32, sizeof(*set32)); +#endif } #endif |