New subject: [PATCH -next] exec: Fix mem leak in kernel_read_file

11 Mar 2019


      From: Al Viro viro@ftp.linux.org.uk on behalf of Al Viro viro@zeniv.linux.org.uk
Sent: Tuesday, February 19, 2019 4:25 AM
To: yuehaibing
Cc: linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org; Dmitry Kasatkin; keescook@chromium.org
Subject: Re: [PATCH -next] exec: Fix mem leak in kernel_read_file
    
On Tue, Feb 19, 2019 at 10:10:38AM +0800, YueHaibing wrote:
...
syzkaller report this:
BUG: memory leak
unreferenced object 0xffffc9000488d000 (size 9195520):
   comm "syz-executor.0", pid 2752, jiffies 4294787496 (age 18.757s)
   hex dump (first 32 bytes):
     ff ff ff ff ff ff ff ff a8 00 00 00 01 00 00 00  ................
     02 00 00 00 00 00 00 00 80 a1 7a c1 ff ff ff ff  ..........z.....
   backtrace:
     [<000000000863775c>] __vmalloc_node mm/vmalloc.c:1795 [inline]
     [<000000000863775c>] __vmalloc_node_flags mm/vmalloc.c:1809 [inline]
     [<000000000863775c>] vmalloc+0x8c/0xb0 mm/vmalloc.c:1831
     [<000000003f668111>] kernel_read_file+0x58f/0x7d0 fs/exec.c:924
     [<000000002385813f>] kernel_read_file_from_fd+0x49/0x80 fs/exec.c:993
     [<0000000011953ff1>] __do_sys_finit_module+0x13b/0x2a0 kernel/module.c:3895
     [<000000006f58491f>] do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
     [<00000000ee78baf4>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
     [<00000000241f889b>] 0xffffffffffffffff
It should goto 'out_free' lable to free allocated buf while kernel_read
fails.
Applied.
This must be applied to stables as well...