2524bb04d8
[ Upstream commit 798b7347e4f29553db4b996393caf12f5b233daf ]
The log of UAF problem is listed below.
BUG: KASAN: use-after-free in jffs2_rmdir+0xa4/0x1cc [jffs2] at addr c1f165fc
Read of size 4 by task rm/8283
=============================================================================
BUG kmalloc-32 (Tainted: P B O ): kasan: bad access detected
-----------------------------------------------------------------------------
INFO: Allocated in 0xbbbbbbbb age=3054364 cpu=0 pid=0
0xb0bba6ef
jffs2_write_dirent+0x11c/0x9c8 [jffs2]
__slab_alloc.isra.21.constprop.25+0x2c/0x44
__kmalloc+0x1dc/0x370
jffs2_write_dirent+0x11c/0x9c8 [jffs2]
jffs2_do_unlink+0x328/0x5fc [jffs2]
jffs2_rmdir+0x110/0x1cc [jffs2]
vfs_rmdir+0x180/0x268
do_rmdir+0x2cc/0x300
ret_from_syscall+0x0/0x3c
INFO: Freed in 0x205b age=3054364 cpu=0 pid=0
0x2e9173
jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
jffs2_garbage_collect_dirent.isra.3+0x21c/0x288 [jffs2]
jffs2_garbage_collect_live+0x16bc/0x1800 [jffs2]
jffs2_garbage_collect_pass+0x678/0x11d4 [jffs2]
jffs2_garbage_collect_thread+0x1e8/0x3b0 [jffs2]
kthread+0x1a8/0x1b0
ret_from_kernel_thread+0x5c/0x64
Call Trace:
[c17ddd20] [c02452d4] kasan_report.part.0+0x298/0x72c (unreliable)
[c17ddda0] [d2509680] jffs2_rmdir+0xa4/0x1cc [jffs2]
[c17dddd0] [c026da04] vfs_rmdir+0x180/0x268
[c17dde00] [c026f4e4] do_rmdir+0x2cc/0x300
[c17ddf40] [c001a658] ret_from_syscall+0x0/0x3c
The root cause is that we don't get "jffs2_inode_info.sem" before
we scan list "jffs2_inode_info.dents" in function jffs2_rmdir.
This patch add codes to get "jffs2_inode_info.sem" before we scan
"jffs2_inode_info.dents" to slove the UAF problem.
Signed-off-by: Zhe Li <lizhe67@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.