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authorRabin Vincent <rabin@rab.in>2014-10-29 23:06:58 +0100
committerSteven Rostedt <rostedt@goodmis.org>2014-10-30 20:58:38 -0400
commit086ba77a6db00ed858ff07451bedee197df868c9 (patch)
tree69dd28823e19c8de176989efc51f03c6a4035e6f
parent4fc409048d5afb1ad853f294b4262ecf2c980a49 (diff)
downloadop-kernel-dev-086ba77a6db00ed858ff07451bedee197df868c9.zip
op-kernel-dev-086ba77a6db00ed858ff07451bedee197df868c9.tar.gz
tracing/syscalls: Ignore numbers outside NR_syscalls' range
ARM has some private syscalls (for example, set_tls(2)) which lie outside the range of NR_syscalls. If any of these are called while syscall tracing is being performed, out-of-bounds array access will occur in the ftrace and perf sys_{enter,exit} handlers. # trace-cmd record -e raw_syscalls:* true && trace-cmd report ... true-653 [000] 384.675777: sys_enter: NR 192 (0, 1000, 3, 4000022, ffffffff, 0) true-653 [000] 384.675812: sys_exit: NR 192 = 1995915264 true-653 [000] 384.675971: sys_enter: NR 983045 (76f74480, 76f74000, 76f74b28, 76f74480, 76f76f74, 1) true-653 [000] 384.675988: sys_exit: NR 983045 = 0 ... # trace-cmd record -e syscalls:* true [ 17.289329] Unable to handle kernel paging request at virtual address aaaaaace [ 17.289590] pgd = 9e71c000 [ 17.289696] [aaaaaace] *pgd=00000000 [ 17.289985] Internal error: Oops: 5 [#1] PREEMPT SMP ARM [ 17.290169] Modules linked in: [ 17.290391] CPU: 0 PID: 704 Comm: true Not tainted 3.18.0-rc2+ #21 [ 17.290585] task: 9f4dab00 ti: 9e710000 task.ti: 9e710000 [ 17.290747] PC is at ftrace_syscall_enter+0x48/0x1f8 [ 17.290866] LR is at syscall_trace_enter+0x124/0x184 Fix this by ignoring out-of-NR_syscalls-bounds syscall numbers. Commit cd0980fc8add "tracing: Check invalid syscall nr while tracing syscalls" added the check for less than zero, but it should have also checked for greater than NR_syscalls. Link: http://lkml.kernel.org/p/1414620418-29472-1-git-send-email-rabin@rab.in Fixes: cd0980fc8add "tracing: Check invalid syscall nr while tracing syscalls" Cc: stable@vger.kernel.org # 2.6.33+ Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_syscalls.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 4dc8b79..29228c4 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -313,7 +313,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
int size;
syscall_nr = trace_get_syscall_nr(current, regs);
- if (syscall_nr < 0)
+ if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
/* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */
@@ -360,7 +360,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
int syscall_nr;
syscall_nr = trace_get_syscall_nr(current, regs);
- if (syscall_nr < 0)
+ if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
/* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */
@@ -567,7 +567,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
int size;
syscall_nr = trace_get_syscall_nr(current, regs);
- if (syscall_nr < 0)
+ if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
return;
@@ -641,7 +641,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
int size;
syscall_nr = trace_get_syscall_nr(current, regs);
- if (syscall_nr < 0)
+ if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
return;
if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
return;
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