f9797c2f20
ftrace_hash is being kfree'ed in ftrace_graph_release(), however the
->buckets field is not. This results in a memory leak that is easily
captured by kmemleak:
unreferenced object 0xffff880038afe000 (size 8192):
comm "trace-cmd", pid 238, jiffies 4294916898 (age 9.736s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff815f561e>] kmemleak_alloc+0x4e/0xb0
[<ffffffff8113964d>] __kmalloc+0x12d/0x1a0
[<ffffffff810bf6d1>] alloc_ftrace_hash+0x51/0x80
[<ffffffff810c0523>] __ftrace_graph_open.isra.39.constprop.46+0xa3/0x100
[<ffffffff810c05e8>] ftrace_graph_open+0x68/0xa0
[<ffffffff8114003d>] do_dentry_open.isra.1+0x1bd/0x2d0
[<ffffffff81140df7>] vfs_open+0x47/0x60
[<ffffffff81150f95>] path_openat+0x2a5/0x1020
[<ffffffff81152d6a>] do_filp_open+0x8a/0xf0
[<ffffffff811411df>] do_sys_open+0x12f/0x200
[<ffffffff811412ce>] SyS_open+0x1e/0x20
[<ffffffff815fa6e0>] entry_SYSCALL_64_fastpath+0x13/0x94
[<ffffffffffffffff>] 0xffffffffffffffff
Link: http://lkml.kernel.org/r/20170525152038.7661-1-lhenriques@suse.com
Cc: stable@vger.kernel.org
Fixes: b9b0c831be ("ftrace: Convert graph filter to use hash tables")
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.