diff options
| author | Vlad Malov <Vlad.Malov@caviumnetworks.com> | 2008-11-18 15:05:46 -0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2008-12-04 17:47:26 +0000 |
| commit | e807f9574e37a3f202e677feaaad1b7c5d2c0db8 (patch) | |
| tree | a9b61e4d8f4e53a81df3bb14df0a4c2b037d8d81 /arch/mips/kernel/scall32-o32.S | |
| parent | feaf3848a813a106f163013af6fcf6c4bfec92d9 (diff) | |
MIPS: Fix potential DOS by untrusted user app.
On a 64 bit kernel if an o32 syscall was made with a syscall number less
than 4000, we would read the function from outside of the bounds of the
syscall table. This led to non-deterministic behavior including system
crashes.
While we were at it we reworked the 32 bit version as well to use fewer
instructions. Both 32 and 64 bit versions are use the same code now.
Signed-off-by: Vlad Malov <Vlad.Malov@caviumnetworks.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/scall32-o32.S')
| -rw-r--r-- | arch/mips/kernel/scall32-o32.S | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S index 759f68066b5..34a4dbd76f2 100644 --- a/arch/mips/kernel/scall32-o32.S +++ b/arch/mips/kernel/scall32-o32.S @@ -262,14 +262,11 @@ bad_alignment: LEAF(sys_syscall) subu t0, a0, __NR_O32_Linux # check syscall number sltiu v0, t0, __NR_O32_Linux_syscalls + 1 + beqz t0, einval # do not recurse sll t1, t0, 3 beqz v0, einval - lw t2, sys_call_table(t1) # syscall routine - li v1, 4000 - __NR_O32_Linux # index of sys_syscall - beq t0, v1, einval # do not recurse - /* Some syscalls like execve get their arguments from struct pt_regs and claim zero arguments in the syscall table. Thus we have to assume the worst case and shuffle around all potential arguments. |