Messages in this thread | | | From | (Eric W. Biederman) | Date | Thu, 03 Dec 2020 14:09:39 -0600 | Subject | [PATCH 0/3] exec: Transform exec_update_mutex into a rw_semaphore |
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Recently syzbot reported[0] that there is a deadlock amongst the users of exec_update_mutex.
The simplest and most robust solution appears to be making exec_update_mutex a read/write lock and having everything execept for exec take the lock for read.
This set of changes upgrades rwsem so it has the functionality needed and uses a rw_semaphore to replace the current mutex.
Eric W. Biederman (3): rwsem: Implement down_read_killable_nested rwsem: Implement down_read_interruptible exec: Transform exec_update_mutex into a rw_semaphore
fs/exec.c | 12 ++++++------ fs/proc/base.c | 10 +++++----- include/linux/rwsem.h | 3 +++ include/linux/sched/signal.h | 11 ++++++----- init/init_task.c | 2 +- kernel/events/core.c | 12 ++++++------ kernel/fork.c | 6 +++--- kernel/kcmp.c | 30 +++++++++++++++--------------- kernel/locking/rwsem.c | 40 ++++++++++++++++++++++++++++++++++++++++ kernel/pid.c | 4 ++-- 10 files changed, 87 insertions(+), 43 deletions(-)
[0] https://lkml.kernel.org/r/00000000000063640c05ade8e3de@google.com
Eric
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