kernel/git/stable/linux.git/net/9p/client.c, branch linux-4.9.y

net/9p: Initialize the iounit field during fid creation

2022-08-25T09:09:27+00:00

commit aa7aeee169480e98cf41d83c01290a37e569be6d upstream. Ensure that the fid's iounit field is set to zero when a new fid is created. Certain 9P operations, such as OPEN and CREATE, allow the server to reply with an iounit size which the client code assigns to the p9_fid struct shortly after the fid is created by p9_fid_create(). On the other hand, an XATTRWALK operation doesn't allow for the server to specify an iounit value. The iounit field of the newly allocated p9_fid struct remained uninitialized in that case. Depending on allocation patterns, the iounit value could have been something reasonable that was carried over from previously freed fids or, in the worst case, could have been arbitrary values from non-fid related usages of the memory location. The bug was detected in the Windows Subsystem for Linux 2 (WSL2) kernel after the uninitialized iounit field resulted in the typical sequence of two getxattr(2) syscalls, one to get the size of an xattr and another after allocating a sufficiently sized buffer to fit the xattr value, to hit an unexpected ERANGE error in the second call to getxattr(2). An uninitialized iounit field would sometimes force rsize to be smaller than the xattr value size in p9_client_read_once() and the 9P server in WSL refused to chunk up the READ on the attr_fid and, instead, returned ERANGE to the client. The virtfs server in QEMU seems happy to chunk up the READ and this problem goes undetected there. Link: https://lkml.kernel.org/r/20220710141402.803295-1-tyhicks@linux.microsoft.com Fixes: ebf46264a004 ("fs/9p: Add support user. xattr") Cc: stable@vger.kernel.org Signed-off-by: Tyler Hicks Reviewed-by: Christian Schoenebeck Signed-off-by: Dominique Martinet [tyhicks: Adjusted context due to: - Lack of fid refcounting introduced in v5.11 commit 6636b6dcc3db ("9p: add refcount to p9_fid struct") - Difference in how buffer sizes are specified v5.16 commit 6e195b0f7c8e ("9p: fix a bunch of checkpatch warnings") - Reimplementation of the fidlist as an IDR in v4.19 commit f28cdf0430fc ("9p: Replace the fidlist with an IDR")] Signed-off-by: Tyler Hicks Signed-off-by: Greg Kroah-Hartman

9p/net: fix memory leak in p9_client_create

2019-03-23T12:19:40+00:00

commit bb06c388fa20ae24cfe80c52488de718a7e3a53f upstream. If msize is less than 4096, we should close and put trans, destroy tagpool, not just free client. This patch fixes that. Link: http://lkml.kernel.org/m/1552464097-142659-1-git-send-email-zhengbin13@huawei.com Cc: stable@vger.kernel.org Fixes: 574d356b7a02 ("9p/net: put a lower bound on msize") Reported-by: Hulk Robot Signed-off-by: zhengbin Signed-off-by: Dominique Martinet Signed-off-by: Greg Kroah-Hartman

9p/net: put a lower bound on msize

2019-01-13T09:03:52+00:00

commit 574d356b7a02c7e1b01a1d9cba8a26b3c2888f45 upstream. If the requested msize is too small (either from command line argument or from the server version reply), we won't get any work done. If it's *really* too small, nothing will work, and this got caught by syzbot recently (on a new kmem_cache_create_usercopy() call) Just set a minimum msize to 4k in both code paths, until someone complains they have a use-case for a smaller msize. We need to check in both mount option and server reply individually because the msize for the first version request would be unchecked with just a global check on clnt->msize. Link: http://lkml.kernel.org/r/1541407968-31350-1-git-send-email-asmadeus@codewreck.org Reported-by: syzbot+0c1d61e4db7db94102ca@syzkaller.appspotmail.com Signed-off-by: Dominique Martinet Cc: Eric Van Hensbergen Cc: Latchesar Ionkov Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

net/9p/client.c: version pointer uninitialized

2018-09-09T18:01:20+00:00

commit 7913690dcc5e18e235769fd87c34143072f5dbea upstream. The p9_client_version() does not initialize the version pointer. If the call to p9pdu_readf() returns an error and version has not been allocated in p9pdu_readf(), then the program will jump to the "error" label and will try to free the version pointer. If version is not initialized, free() will be called with uninitialized, garbage data and will provoke a crash. Link: http://lkml.kernel.org/r/20180709222943.19503-1-tomasbortoli@gmail.com Signed-off-by: Tomas Bortoli Reported-by: syzbot+65c6b72f284a39d416b4@syzkaller.appspotmail.com Reviewed-by: Jun Piao Reviewed-by: Yiwen Jiang Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: Andrew Morton Cc: stable@vger.kernel.org Signed-off-by: Dominique Martinet Signed-off-by: Greg Kroah-Hartman

net/9p: Switch to wait_event_killable()

2017-11-30T08:39:09+00:00

commit 9523feac272ccad2ad8186ba4fcc89103754de52 upstream. Because userspace gets Very Unhappy when calls like stat() and execve() return -EINTR on 9p filesystem mounts. For instance, when bash is looking in PATH for things to execute and some SIGCHLD interrupts stat(), bash can throw a spurious 'command not found' since it doesn't retry the stat(). In practice, hitting the problem is rare and needs a really slow/bogged down 9p server. Signed-off-by: Tuomas Tynkkynen Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

p9_client_readdir() fix

2017-05-03T15:36:38+00:00

commit 71d6ad08379304128e4bdfaf0b4185d54375423e upstream. Don't assume that server is sane and won't return more data than asked for. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

remove lots of IS_ERR_VALUE abuses

2016-05-27T22:26:11+00:00

Most users of IS_ERR_VALUE() in the kernel are wrong, as they pass an 'int' into a function that takes an 'unsigned long' argument. This happens to work because the type is sign-extended on 64-bit architectures before it gets converted into an unsigned type. However, anything that passes an 'unsigned short' or 'unsigned int' argument into IS_ERR_VALUE() is guaranteed to be broken, as are 8-bit integers and types that are wider than 'unsigned long'. Andrzej Hajda has already fixed a lot of the worst abusers that were causing actual bugs, but it would be nice to prevent any users that are not passing 'unsigned long' arguments. This patch changes all users of IS_ERR_VALUE() that I could find on 32-bit ARM randconfig builds and x86 allmodconfig. For the moment, this doesn't change the definition of IS_ERR_VALUE() because there are probably still architecture specific users elsewhere. Almost all the warnings I got are for files that are better off using 'if (err)' or 'if (err < 0)'. The only legitimate user I could find that we get a warning for is the (32-bit only) freescale fman driver, so I did not remove the IS_ERR_VALUE() there but changed the type to 'unsigned long'. For 9pfs, I just worked around one user whose calling conventions are so obscure that I did not dare change the behavior. I was using this definition for testing: #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \ unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO)) which ends up making all 16-bit or wider types work correctly with the most plausible interpretation of what IS_ERR_VALUE() was supposed to return according to its users, but also causes a compile-time warning for any users that do not pass an 'unsigned long' argument. I suggested this approach earlier this year, but back then we ended up deciding to just fix the users that are obviously broken. After the initial warning that caused me to get involved in the discussion (fs/gfs2/dir.c) showed up again in the mainline kernel, Linus asked me to send the whole thing again. [ Updated the 9p parts as per Al Viro - Linus ] Signed-off-by: Arnd Bergmann Cc: Andrzej Hajda Cc: Andrew Morton Link: https://lkml.org/lkml/2016/1/7/363 Link: https://lkml.org/lkml/2016/5/27/486 Acked-by: Srinivas Kandagatla # For nvmem part Signed-off-by: Linus Torvalds

9p: ensure err is initialized to 0 in p9_client_read/write

2015-08-23T01:35:02+00:00

Some use of those functions were providing unitialized values to those functions. Notably, when reading 0 bytes from an empty file on a 9P filesystem, the return code of read() was not 0. Tested with this simple program: #include #include #include #include #include int main(int argc, const char **argv) { assert(argc == 2); char buffer[256]; int fd = open(argv[1], O_RDONLY|O_NOCTTY); assert(fd >= 0); assert(read(fd, buffer, 0) == 0); return 0; } Cc: stable@vger.kernel.org # v4.1 Signed-off-by: Vincent Bernat Signed-off-by: Al Viro

9p: cope with bogus responses from server in p9_client_{read,write}

2015-07-04T20:17:39+00:00

if server claims to have written/read more than we'd told it to, warn and cap the claimed byte count to avoid advancing more than we are ready to.

p9_client_write(): avoid double p9_free_req()

2015-07-04T20:11:05+00:00

Braino in "9p: switch p9_client_write() to passing it struct iov_iter *"; if response is impossible to parse and we discard the request, get the out of the loop right there. Cc: stable@vger.kernel.org Signed-off-by: Al Viro