score: fix off-by-one index into syscall table

If the provided system call number is equal to __NR_syscalls, the
current check will pass and a function pointer just after the system
call table may be called, since sys_call_table is an array with total
size __NR_syscalls.

Whether or not this is a security bug depends on what the compiler puts
immediately after the system call table.  It's likely that this won't do
anything bad because there is an additional NULL check on the syscall
entry, but if there happens to be a non-NULL value immediately after the
system call table, this may result in local privilege escalation.

Signed-off-by: Dan Rosenberg <[email protected]>
Cc: <[email protected]>
Cc: Chen Liqin <[email protected]>
Cc: Lennox Wu <[email protected]>
Cc: Eugene Teo <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions