cgroup: Fix memory leak when parsing multiple source parameters
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: 8d2451f4994f ("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>
1 file changed
