Skip to content
Snippets Groups Projects
  1. Mar 02, 2016
  2. Mar 02, 2015
  3. Dec 09, 2014
    • Al Viro's avatar
      put iov_iter into msghdr · c0371da6
      Al Viro authored
      
      Note that the code _using_ ->msg_iter at that point will be very
      unhappy with anything other than unshifted iovec-backed iov_iter.
      We still need to convert users to proper primitives.
      
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      c0371da6
  4. Nov 24, 2014
  5. Jan 19, 2014
  6. Nov 21, 2013
    • Hannes Frederic Sowa's avatar
      net: rework recvmsg handler msg_name and msg_namelen logic · f3d33426
      Hannes Frederic Sowa authored
      
      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: default avatarEric Dumazet <eric.dumazet@gmail.com>
      Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f3d33426
  7. Jul 23, 2012
    • Weiping Pan's avatar
      rds: set correct msg_namelen · 06b6a1cf
      Weiping Pan authored
      
      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: default avatarWeiping Pan <wpan@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      06b6a1cf
  8. Mar 20, 2012
  9. Oct 31, 2011
  10. Oct 21, 2010
  11. Sep 09, 2010
  12. Aug 19, 2010
  13. Apr 20, 2010
  14. Mar 30, 2010
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      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: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  15. Nov 30, 2009
  16. Aug 24, 2009
  17. Jul 20, 2009
  18. Feb 27, 2009
Loading