kernel/linux.git/net/9p/protocol.c, branch v6.19.11

net: 9p: avoid freeing uninit memory in p9pdu_vreadf

2023-12-12T20:44:30+00:00

If some of p9pdu_readf() calls inside case 'T' in p9pdu_vreadf() fails, the error path is not handled properly. *wnames or members of *wnames array may be left uninitialized and invalidly freed. Initialize *wnames to NULL in beginning of case 'T'. Initialize the first *wnames array element to NULL and nullify the failing *wnames element so that the error path freeing loop stops on the first NULL element and doesn't proceed further. Found by Linux Verification Center (linuxtesting.org). Fixes: ace51c4dd2f9 ("9p: add new protocol support code") Signed-off-by: Fedor Pchelkin Message-ID: <20231206200913.16135-1-pchelkin@ispras.ru> Cc: stable@vger.kernel.org Reviewed-by: Simon Horman Reviewed-by: Christian Schoenebeck Signed-off-by: Dominique Martinet

net/9p: add p9_msg_buf_size()

2022-10-04T22:05:41+00:00

This new function calculates a buffer size suitable for holding the intended 9p request or response. For rather small message types (which applies to almost all 9p message types actually) simply use hard coded values. For some variable-length and potentially large message types calculate a more precise value according to what data is actually transmitted to avoid unnecessarily huge buffers. So p9_msg_buf_size() divides the individual 9p message types into 3 message size categories: - dynamically calculated message size (i.e. potentially large) - 8k hard coded message size - 4k hard coded message size As for the latter two hard coded message types: for most 9p message types it is pretty obvious whether they would always fit into 4k or 8k. But for some of them it depends on the maximum directory entry name length allowed by OS and filesystem for determining into which of the two size categories they would fit into. Currently Linux supports directory entry names up to NAME_MAX (255), however when comparing the limitation of individual filesystems, ReiserFS theoretically supports up to slightly below 4k long names. So in order to make this code more future proof, and as revisiting it later on is a bit tedious and has the potential to miss out details, the decision [1] was made to take 4k as basis as for max. name length. Link: https://lkml.kernel.org/r/bd6be891cf67e867688e8c8796d06408bfafa0d9.1657920926.git.linux_oss@crudebyte.com Link: https://lore.kernel.org/all/5564296.oo812IJUPE@silver/ [1] Signed-off-by: Christian Schoenebeck Signed-off-by: Dominique Martinet

9p: convert to advancing variant of iov_iter_get_pages_alloc()

2022-08-09T02:37:23+00:00

that one is somewhat clumsier than usual and needs serious testing. Signed-off-by: Al Viro

9p: fix a bunch of checkpatch warnings

2021-11-04T12:04:25+00:00

Sohaib Mohamed started a serie of tiny and incomplete checkpatch fixes but seemingly stopped halfway -- take over and do most of it. This is still missing net/9p/trans* and net/9p/protocol.c for a later time... Link: http://lkml.kernel.org/r/20211102134608.1588018-3-dominique.martinet@atmark-techno.com Signed-off-by: Dominique Martinet

9p: fix file headers

2021-11-03T08:45:04+00:00

- add missing SPDX-License-Identifier - remove (sometimes incorrect) file name from file header Link: http://lkml.kernel.org/r/20211102134608.1588018-2-dominique.martinet@atmark-techno.com Signed-off-by: Dominique Martinet

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188

2019-05-30T18:29:21+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to free software foundation 51 franklin street fifth floor boston ma 02111 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 27 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Richard Fontana Reviewed-by: Alexios Zavras Reviewed-by: Steve Winslow Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528170026.981318839@linutronix.de Signed-off-by: Greg Kroah-Hartman

9p: p9dirent_read: check network-provided name length

2018-09-07T16:52:29+00:00

strcpy to dirent->d_name could overflow the buffer, use strscpy to check the provided string length and error out if the size was too big. While we are here, make the function return an error when the pdu parsing failed, instead of returning the pdu offset as if it had been a success... Link: http://lkml.kernel.org/r/1536339057-21974-4-git-send-email-asmadeus@codewreck.org Addresses-Coverity-ID: 139133 ("Copy into fixed size buffer") Signed-off-by: Dominique Martinet

9p: do not trust pdu content for stat item size

2018-09-07T16:40:06+00:00

v9fs_dir_readdir() could deadloop if a struct was sent with a size set to -2 Link: http://lkml.kernel.org/r/1536134432-11997-1-git-send-email-asmadeus@codewreck.org Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88021 Signed-off-by: Gertjan Halkes Signed-off-by: Dominique Martinet

9p: clear dangling pointers in p9stat_free

2018-08-29T04:39:57+00:00

p9stat_free is more of a cleanup function than a 'free' function as it only frees the content of the struct; there are chances of use-after-free if it is improperly used (e.g. p9stat_free called twice as it used to be possible to) Clearing dangling pointers makes the function idempotent and safer to use. Link: http://lkml.kernel.org/r/1535410108-20650-2-git-send-email-asmadeus@codewreck.org Signed-off-by: Dominique Martinet Reported-by: syzbot+d4252148d198410b864f@syzkaller.appspotmail.com

9p/net/protocol.c: return -ENOMEM when kmalloc() failed

2018-08-13T00:21:44+00:00

We should return -ENOMEM to upper user when kmalloc failed to indicate accurate errno. Link: http://lkml.kernel.org/r/5B4552C5.60000@huawei.com Signed-off-by: Jun Piao Reviewed-by: Yiwen Jiang Reviewed-by: Andrew Morton Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: Andrew Morton Signed-off-by: Dominique Martinet