This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size <= sizeof(struct sockaddr_storage)
to return msg_name to the user.
This prevents numerous uninitialized memory leaks we had in the
recvmsg handlers and makes it harder for new code to accidentally leak
uninitialized memory.
Optimize for the case recvfrom is called with NULL as address. We don't
need to copy the address at all, so set it to NULL before invoking the
recvmsg handler. We can do so, because all the recvmsg handlers must
cope with the case a plain read() is called on them. read() also sets
msg_name to NULL.
Also document these changes in include/linux/net.h as suggested by David
Miller.
Changes since RFC:
Set msg->msg_name = NULL if user specified a NULL in msg_name but had a
non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't
affect sendto as it would bail out earlier while trying to copy-in the
address. It also more naturally reflects the logic by the callers of
verify_iovec.
With this change in place I could remove "
if (!uaddr || msg_sys->msg_namelen == 0)
msg->msg_name = NULL
".
This change does not alter the user visible error logic as we ignore
msg_namelen as long as msg_name is NULL.
Also remove two unnecessary curly brackets in ___sys_recvmsg and change
comments to netdev style.
Cc: David Miller <davem@davemloft.net>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jay Fenlason (fenlason@redhat.com) found a bug,
that recvfrom() on an RDS socket can return the contents of random kernel
memory to userspace if it was called with a address length larger than
sizeof(struct sockaddr_in).
rds_recvmsg() also fails to set the addr_len paramater properly before
returning, but that's just a bug.
There are also a number of cases wher recvfrom() can return an entirely bogus
address. Anything in rds_recvmsg() that returns a non-negative value but does
not go through the "sin = (struct sockaddr_in *)msg->msg_name;" code path
at the end of the while(1) loop will return up to 128 bytes of kernel memory
to userspace.
And I write two test programs to reproduce this bug, you will see that in
rds_server, fromAddr will be overwritten and the following sock_fd will be
destroyed.
Yes, it is the programmer's fault to set msg_namelen incorrectly, but it is
better to make the kernel copy the real length of address to user space in
such case.
How to run the test programs ?
I test them on 32bit x86 system, 3.5.0-rc7.
1 compile
gcc -o rds_client rds_client.c
gcc -o rds_server rds_server.c
2 run ./rds_server on one console
3 run ./rds_client on another console
4 you will see something like:
server is waiting to receive data...
old socket fd=3
server received data from client:data from client
msg.msg_namelen=32
new socket fd=-1067277685
sendmsg()
: Bad file descriptor
/***************** rds_client.c ********************/
int main(void)
{
int sock_fd;
struct sockaddr_in serverAddr;
struct sockaddr_in toAddr;
char recvBuffer[128] = "data from client";
struct msghdr msg;
struct iovec iov;
sock_fd = socket(AF_RDS, SOCK_SEQPACKET, 0);
if (sock_fd < 0) {
perror("create socket error\n");
exit(1);
}
memset(&serverAddr, 0, sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
serverAddr.sin_port = htons(4001);
if (bind(sock_fd, (struct sockaddr*)&serverAddr, sizeof(serverAddr)) < 0) {
perror("bind() error\n");
close(sock_fd);
exit(1);
}
memset(&toAddr, 0, sizeof(toAddr));
toAddr.sin_family = AF_INET;
toAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
toAddr.sin_port = htons(4000);
msg.msg_name = &toAddr;
msg.msg_namelen = sizeof(toAddr);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_iov->iov_base = recvBuffer;
msg.msg_iov->iov_len = strlen(recvBuffer) + 1;
msg.msg_control = 0;
msg.msg_controllen = 0;
msg.msg_flags = 0;
if (sendmsg(sock_fd, &msg, 0) == -1) {
perror("sendto() error\n");
close(sock_fd);
exit(1);
}
printf("client send data:%s\n", recvBuffer);
memset(recvBuffer, '\0', 128);
msg.msg_name = &toAddr;
msg.msg_namelen = sizeof(toAddr);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_iov->iov_base = recvBuffer;
msg.msg_iov->iov_len = 128;
msg.msg_control = 0;
msg.msg_controllen = 0;
msg.msg_flags = 0;
if (recvmsg(sock_fd, &msg, 0) == -1) {
perror("recvmsg() error\n");
close(sock_fd);
exit(1);
}
printf("receive data from server:%s\n", recvBuffer);
close(sock_fd);
return 0;
}
/***************** rds_server.c ********************/
int main(void)
{
struct sockaddr_in fromAddr;
int sock_fd;
struct sockaddr_in serverAddr;
unsigned int addrLen;
char recvBuffer[128];
struct msghdr msg;
struct iovec iov;
sock_fd = socket(AF_RDS, SOCK_SEQPACKET, 0);
if(sock_fd < 0) {
perror("create socket error\n");
exit(0);
}
memset(&serverAddr, 0, sizeof(serverAddr));
serverAddr.sin_family = AF_INET;
serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
serverAddr.sin_port = htons(4000);
if (bind(sock_fd, (struct sockaddr*)&serverAddr, sizeof(serverAddr)) < 0) {
perror("bind error\n");
close(sock_fd);
exit(1);
}
printf("server is waiting to receive data...\n");
msg.msg_name = &fromAddr;
/*
* I add 16 to sizeof(fromAddr), ie 32,
* and pay attention to the definition of fromAddr,
* recvmsg() will overwrite sock_fd,
* since kernel will copy 32 bytes to userspace.
*
* If you just use sizeof(fromAddr), it works fine.
* */
msg.msg_namelen = sizeof(fromAddr) + 16;
/* msg.msg_namelen = sizeof(fromAddr); */
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_iov->iov_base = recvBuffer;
msg.msg_iov->iov_len = 128;
msg.msg_control = 0;
msg.msg_controllen = 0;
msg.msg_flags = 0;
while (1) {
printf("old socket fd=%d\n", sock_fd);
if (recvmsg(sock_fd, &msg, 0) == -1) {
perror("recvmsg() error\n");
close(sock_fd);
exit(1);
}
printf("server received data from client:%s\n", recvBuffer);
printf("msg.msg_namelen=%d\n", msg.msg_namelen);
printf("new socket fd=%d\n", sock_fd);
strcat(recvBuffer, "--data from server");
if (sendmsg(sock_fd, &msg, 0) == -1) {
perror("sendmsg()\n");
close(sock_fd);
exit(1);
}
}
close(sock_fd);
return 0;
}
Signed-off-by: Weiping Pan <wpan@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The RDS protocol has lots of functions that should be
declared static. rds_message_get/add_version_extension is
removed since it defined but never used.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct rds_rdma_notify contains a 32 bits hole on 64bit arches,
make sure it is zeroed before copying it to user.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Define a new function to return the waitqueue of a "struct sock".
static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
return sk->sk_sleep;
}
Change all read occurrences of sk_sleep by a call to this function.
Needed for a future RCU conversion. sk_sleep wont be a field directly
available.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Not including net/atm/
Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that rdma and tcp transports will be modularized,
we need to export a number of functions so they can call them.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Completion or congestion notifications were not being checked
if the socket went to sleep. This patch fixes that.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Upon receiving a datagram from the transport, RDS parses the
headers and potentially queues an ACK.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
