diff options
authorDan Rosenberg <drosenberg@vsecurity.com>2012-01-20 14:34:27 -0800
committerPaul Gortmaker <paul.gortmaker@windriver.com>2012-05-17 11:21:39 -0400
commit861743b9f32cdf4d3e4af10a2c4f13ad9001c9f2 (patch)
parentaac3f5904beea76bcd6da3e047586f4f3b0f0179 (diff)
score: fix off-by-one index into syscall table
commit c25a785d6647984505fa165b5cd84cfc9a95970b upstream. 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 <drosenberg@vsecurity.com> Cc: <stable@vger.kernel.org> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Eugene Teo <eugeneteo@kernel.sg> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/score/kernel/entry.S b/arch/score/kernel/entry.S
index 577abba3fac6..83bb96079c43 100644
--- a/arch/score/kernel/entry.S
+++ b/arch/score/kernel/entry.S
@@ -408,7 +408,7 @@ ENTRY(handle_sys)
sw r9, [r0, PT_EPC]
cmpi.c r27, __NR_syscalls # check syscall number
- bgtu illegal_syscall
+ bgeu illegal_syscall
slli r8, r27, 2 # get syscall routine
la r11, sys_call_table