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| author | Zach Reizner <zachr@google.com> | 2021-03-26 22:11:16 -0400 |
|---|---|---|
| committer | Laurent Vivier <laurent@vivier.eu> | 2021-03-27 16:48:45 +0100 |
| commit | 4a1e6bce2308b720d79d5ea0a3d24501c89bd80c (patch) | |
| tree | 5a37c203e8888dd5eb15f2f1e26be5e74d9c6e94 | |
| parent | 23fff7a17f47420797ac6480147941612152a9ad (diff) | |
| download | qemu-4a1e6bce2308b720d79d5ea0a3d24501c89bd80c.zip qemu-4a1e6bce2308b720d79d5ea0a3d24501c89bd80c.tar.gz qemu-4a1e6bce2308b720d79d5ea0a3d24501c89bd80c.tar.bz2 | |
linux-user: allow NULL msg in recvfrom
The kernel allows a NULL msg in recvfrom so that he size of the next
message may be queried before allocating a correctly sized buffer. This
change allows the syscall translator to pass along the NULL msg pointer
instead of returning early with EFAULT.
Signed-off-by: Zach Reizner <zachr@google.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <CAFNex=DvFCq=AQf+=19fTfw-T8eZZT=3NnFFm2JMFvVr5QgQyA@mail.gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
| -rw-r--r-- | linux-user/syscall.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 1e50857..294779c 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -3679,9 +3679,14 @@ static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags, void *host_msg; abi_long ret; - host_msg = lock_user(VERIFY_WRITE, msg, len, 0); - if (!host_msg) - return -TARGET_EFAULT; + if (!msg) { + host_msg = NULL; + } else { + host_msg = lock_user(VERIFY_WRITE, msg, len, 0); + if (!host_msg) { + return -TARGET_EFAULT; + } + } if (target_addr) { if (get_user_u32(addrlen, target_addrlen)) { ret = -TARGET_EFAULT; |