diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2019-07-18 10:47:47 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-08-06 19:08:13 +0200 |
| commit | 1b3ecd64aaae6bd6fa97059a29f07a2b2e20b2c9 (patch) | |
| tree | 210a1edd216a16262a5c701c90d63e6186f8db6b /kernel/stacktrace.c | |
| parent | 71494c7b6f0c70b5a291e5ce5dd1d2cd77599b31 (diff) | |
stacktrace: Force USER_DS for stack_trace_save_user()
[ Upstream commit cac9b9a4b08304f11daace03b8b48659355e44c1 ]
When walking userspace stacks, USER_DS needs to be set, otherwise
access_ok() will not function as expected.
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vegard Nossum <vegard.nossum@oracle.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lkml.kernel.org/r/20190718085754.GM3402@hirez.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/stacktrace.c')
| -rw-r--r-- | kernel/stacktrace.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index 36139de0a3c4..899b726c9e98 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -226,12 +226,17 @@ unsigned int stack_trace_save_user(unsigned long *store, unsigned int size) .store = store, .size = size, }; + mm_segment_t fs; /* Trace user stack if not a kernel thread */ if (!current->mm) return 0; + fs = get_fs(); + set_fs(USER_DS); arch_stack_walk_user(consume_entry, &c, task_pt_regs(current)); + set_fs(fs); + return c.len; } #endif |