fs/exec: fix use after free in execve
"file" can be already freed if bprm->file is NULL after
search_binary_handler() return. binfmt_script will do exactly that for
example. If the VM reuses the file after fput run(), this will result in
a use ater free.
So obtain d_is_su before search_binary_handler() runs.
This should explain this crash:
[25333.009554] Unable to handle kernel NULL pointer dereference at virtual address 00000185
[..]
[25333.009918] [2: am:21861] PC is at do_execve+0x354/0x474
Change-Id: I2a8a814d1c0aa75625be83cb30432cf13f1a0681
1 file changed