linux-stable/kernel/cgroup
Qinglang Miao bf81221a40 cgroup: Fix memory leak when parsing multiple source parameters
commit 2d18e54dd8 upstream.

A memory leak is found in cgroup1_parse_param() when multiple source
parameters overwrite fc->source in the fs_context struct without free.

unreferenced object 0xffff888100d930e0 (size 16):
  comm "mount", pid 520, jiffies 4303326831 (age 152.783s)
  hex dump (first 16 bytes):
    74 65 73 74 6c 65 61 6b 00 00 00 00 00 00 00 00  testleak........
  backtrace:
    [<000000003e5023ec>] kmemdup_nul+0x2d/0xa0
    [<00000000377dbdaa>] vfs_parse_fs_string+0xc0/0x150
    [<00000000cb2b4882>] generic_parse_monolithic+0x15a/0x1d0
    [<000000000f750198>] path_mount+0xee1/0x1820
    [<0000000004756de2>] do_mount+0xea/0x100
    [<0000000094cafb0a>] __x64_sys_mount+0x14b/0x1f0

Fix this bug by permitting a single source parameter and rejecting with
an error all subsequent ones.

Fixes: 8d2451f499 ("cgroup1: switch to option-by-option parsing")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Reviewed-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-06 14:56:51 +01:00
..
cgroup-internal.h fs_parse: fold fs_parameter_desc/fs_parameter_spec 2020-02-07 14:48:37 -05:00
cgroup-v1.c cgroup: Fix memory leak when parsing multiple source parameters 2021-01-06 14:56:51 +01:00
cgroup.c cgroup: Zero sized write should be no-op 2020-09-30 13:52:06 -04:00
cpuset.c cpuset: fix race between hotplug work and later CPU offline 2020-12-30 11:54:11 +01:00
debug.c kernel: cgroup: fix misuse of %x 2019-05-06 08:47:48 -07:00
freezer.c cgroup: freezer: don't change task and cgroups status unnecessarily 2019-11-07 07:38:41 -08:00
legacy_freezer.c cgroup: rename freezer.c into legacy_freezer.c 2019-04-19 11:26:48 -07:00
Makefile cgroup: cgroup v2 freezer 2019-04-19 11:26:48 -07:00
namespace.c nsproxy: add struct nsset 2020-05-09 13:57:12 +02:00
pids.c clone3: allow spawning processes into cgroups 2020-02-12 17:57:51 -05:00
rdma.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 451 2019-06-19 17:09:08 +02:00
rstat.c cgroup: unexport cgroup_rstat_updated 2020-06-29 09:09:08 -06:00