- Kernel - mailweb.openeuler.org

[PATCH OLK-5.10] nilfs2: fix potential bug in end_buffer_async_write
by Zizhi Wo 11 Apr '24

11 Apr '24

From: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> stable inclusion from stable-v5.10.210 commit f3e4963566f58726d3265a727116a42b591f6596 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2FP CVE: CVE-2024-26685 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 5bc09b397cbf1221f8a8aacb1152650c9195b02b upstream. According to a syzbot report, end_buffer_async_write(), which handles the completion of block device writes, may detect abnormal condition of the buffer async_write flag and cause a BUG_ON failure when using nilfs2. Nilfs2 itself does not use end_buffer_async_write(). But, the async_write flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") as a means of resolving double list insertion of dirty blocks in nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the resulting crash. This modification is safe as long as it is used for file data and b-tree node blocks where the page caches are independent. However, it was irrelevant and redundant to also introduce async_write for segment summary and super root blocks that share buffers with the backing device. This led to the possibility that the BUG_ON check in end_buffer_async_write would fail as described above, if independent writebacks of the backing device occurred in parallel. The use of async_write for segment summary buffers has already been removed in a previous change. Fix this issue by removing the manipulation of the async_write flag for the remaining super root block buffer. Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com Fixes: 7f42ec394156 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+5c04210f7c7f897c1e7f(a)syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Zizhi Wo <wozizhi(a)huawei.com> --- fs/nilfs2/segment.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 418055ac910b..be0ca35b8aa4 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1707,7 +1707,6 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - set_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { if (bh->b_page != bd_page) { lock_page(bd_page); @@ -1718,6 +1717,7 @@ static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) } break; } + set_buffer_async_write(bh); if (bh->b_page != fs_page) { nilfs_begin_page_io(fs_page); fs_page = bh->b_page; @@ -1803,7 +1803,6 @@ static void nilfs_abort_logs(struct list_head *logs, int err) list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { - clear_buffer_async_write(bh); if (bh == segbuf->sb_super_root) { clear_buffer_uptodate(bh); if (bh->b_page != bd_page) { @@ -1812,6 +1811,7 @@ static void nilfs_abort_logs(struct list_head *logs, int err) } break; } + clear_buffer_async_write(bh); if (bh->b_page != fs_page) { nilfs_end_page_io(fs_page, err); fs_page = bh->b_page; @@ -1899,8 +1899,9 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) BIT(BH_Delay) | BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Redirected)); - set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh == segbuf->sb_super_root) { + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); if (bh->b_page != bd_page) { end_page_writeback(bd_page); bd_page = bh->b_page; @@ -1908,6 +1909,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) update_sr = true; break; } + set_mask_bits(&bh->b_state, clear_bits, set_bits); if (bh->b_page != fs_page) { nilfs_end_page_io(fs_page, 0); fs_page = bh->b_page; -- 2.39.2

2 1

[PATCH openEuler-1.0-LTS 0/2] Fix CVE-2024-26685
by Zizhi Wo 11 Apr '24

11 Apr '24

Fixup the CVE-2024-26685 Ryusuke Konishi (2): nilfs2: fix buffer corruption due to concurrent device reads nilfs2: fix potential bug in end_buffer_async_write fs/nilfs2/segbuf.c | 6 ++++++ fs/nilfs2/segment.c | 15 ++++++++++++--- fs/nilfs2/super.c | 23 ++++++++++++++++++++++- 3 files changed, 40 insertions(+), 4 deletions(-) -- 2.39.2

2 3

[PATCH OLK-5.10 0/2] Fix CVE-2024-26685
by Zizhi Wo 11 Apr '24

11 Apr '24

Fix up the CVE-2024-26685 Ryusuke Konishi (2): nilfs2: fix buffer corruption due to concurrent device reads nilfs2: fix potential bug in end_buffer_async_write fs/nilfs2/segbuf.c | 6 ++++++ fs/nilfs2/segment.c | 15 ++++++++++++--- fs/nilfs2/super.c | 23 ++++++++++++++++++++++- 3 files changed, 40 insertions(+), 4 deletions(-) -- 2.39.2

2 3

[PATCH OLK-5.10] ceph: prevent use-after-free in encode_cap_msg()
by Long Li 11 Apr '24

11 Apr '24

From: Rishabh Dave <ridave(a)redhat.com> stable inclusion from stable-v5.10.167 commit 8180d0c27b93a6eb60da1b08ea079e3926328214 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2GN CVE: CVE-2024-26689 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=… -------------------------------- commit cda4672da1c26835dcbd7aec2bfed954eda9b5ef upstream. In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error was caught by KASAN at this line - 'ceph_buffer_get(arg->xattr_buf);'. This implies before the refcount could be increment here, it was freed. In same file, in "handle_cap_grant()" refcount is decremented by this line - 'ceph_buffer_put(ci->i_xattrs.blob);'. It appears that a race occurred and resource was freed by the latter line before the former line could increment it. encode_cap_msg() is called by __send_cap() and __send_cap() is called by ceph_check_caps() after calling __prep_cap(). __prep_cap() is where arg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot where the refcount must be increased to prevent "use after free" error. Cc: stable(a)vger.kernel.org Link: https://tracker.ceph.com/issues/59259 Signed-off-by: Rishabh Dave <ridave(a)redhat.com> Reviewed-by: Jeff Layton <jlayton(a)kernel.org> Reviewed-by: Xiubo Li <xiubli(a)redhat.com> Signed-off-by: Ilya Dryomov <idryomov(a)gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Long Li <leo.lilong(a)huawei.com> --- fs/ceph/caps.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index b0cf79b0dc49..8e43d07ffa8b 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -1402,7 +1402,7 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap, if (flushing & CEPH_CAP_XATTR_EXCL) { arg->old_xattr_buf = __ceph_build_xattrs_blob(ci); arg->xattr_version = ci->i_xattrs.version; - arg->xattr_buf = ci->i_xattrs.blob; + arg->xattr_buf = ceph_buffer_get(ci->i_xattrs.blob); } else { arg->xattr_buf = NULL; arg->old_xattr_buf = NULL; @@ -1468,6 +1468,7 @@ static void __send_cap(struct cap_msg_args *arg, struct ceph_inode_info *ci) encode_cap_msg(msg, arg); ceph_con_send(&arg->session->s_con, msg); ceph_buffer_put(arg->old_xattr_buf); + ceph_buffer_put(arg->xattr_buf); if (arg->wake) wake_up_all(&ci->i_cap_wq); } -- 2.31.1

2 1

[PATCH openEuler-1.0-LTS] [Backport] rcu-tasks: Eliminate deadlocks involving do_exit() and RCU tasks
by Liu Chuang 11 Apr '24

11 Apr '24

From: "Paul E. McKenney" <paulmck(a)kernel.org> maillist inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9FXM5 Reference: https://lore.kernel.org/all/20240207110846.25168-1-qiang.zhang1211@gmail.co… -------------------------------- commit bc31e6cb27a9334140ff2f0a209d59b08bc0bc8c upstream. Holding a mutex across synchronize_rcu_tasks() and acquiring that same mutex in code called from do_exit() after its call to exit_tasks_rcu_start() but before its call to exit_tasks_rcu_stop() results in deadlock. This is by design, because tasks that are far enough into do_exit() are no longer present on the tasks list, making it a bit difficult for RCU Tasks to find them, let alone wait on them to do a voluntary context switch. However, such deadlocks are becoming more frequent. In addition, lockdep currently does not detect such deadlocks and they can be difficult to reproduce. In addition, if a task voluntarily context switches during that time (for example, if it blocks acquiring a mutex), then this task is in an RCU Tasks quiescent state. And with some adjustments, RCU Tasks could just as well take advantage of that fact. This commit therefore eliminates these deadlock by replacing the SRCU-based wait for do_exit() completion with per-CPU lists of tasks currently exiting. A given task will be on one of these per-CPU lists for the same period of time that this task would previously have been in the previous SRCU read-side critical section. These lists enable RCU Tasks to find the tasks that have already been removed from the tasks list, but that must nevertheless be waited upon. The RCU Tasks grace period gathers any of these do_exit() tasks that it must wait on, and adds them to the list of holdouts. Per-CPU locking and get_task_struct() are used to synchronize addition to and removal from these lists. Link: https://lore.kernel.org/all/20240118021842.290665-1-chenzhongjin@huawei.com/ Reported-by: Chen Zhongjin <chenzhongjin(a)huawei.com> Signed-off-by: Paul E. McKenney <paulmck(a)kernel.org> Signed-off-by: Zqiang <qiang.zhang1211(a)gmail.com> --- include/linux/sched.h | 1 + init/init_task.c | 1 + kernel/fork.c | 1 + kernel/rcu/update.c | 65 ++++++++++++++++++++++++++++++------------- 4 files changed, 49 insertions(+), 19 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 8fd8c5b7cdc6..2dff665cc33a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -705,6 +705,7 @@ struct task_struct { u8 rcu_tasks_idx; int rcu_tasks_idle_cpu; struct list_head rcu_tasks_holdout_list; + struct list_head rcu_tasks_exit_list; #endif /* #ifdef CONFIG_TASKS_RCU */ struct sched_info sched_info; diff --git a/init/init_task.c b/init/init_task.c index b312a045f4b9..4bc8502d33d3 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -139,6 +139,7 @@ struct task_struct init_task .rcu_tasks_holdout = false, .rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list), .rcu_tasks_idle_cpu = -1, + .rcu_tasks_exit_list = LIST_HEAD_INIT(init_task.rcu_tasks_exit_list), #endif #ifdef CONFIG_CPUSETS .mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq), diff --git a/kernel/fork.c b/kernel/fork.c index bfc4534ff116..8c96c517e09e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1711,6 +1711,7 @@ static inline void rcu_copy_process(struct task_struct *p) p->rcu_tasks_holdout = false; INIT_LIST_HEAD(&p->rcu_tasks_holdout_list); p->rcu_tasks_idle_cpu = -1; + INIT_LIST_HEAD(&p->rcu_tasks_exit_list); #endif /* #ifdef CONFIG_TASKS_RCU */ } diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 759ea6881a58..af9a43172d0e 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -527,7 +527,8 @@ static DECLARE_WAIT_QUEUE_HEAD(rcu_tasks_cbs_wq); static DEFINE_RAW_SPINLOCK(rcu_tasks_cbs_lock); /* Track exiting tasks in order to allow them to be waited for. */ -DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu); +static LIST_HEAD(rtp_exit_list); +static DEFINE_RAW_SPINLOCK(rtp_exit_list_lock); /* Control stall timeouts. Disable with <= 0, otherwise jiffies till stall. */ #define RCU_TASK_STALL_TIMEOUT (HZ * 60 * 10) @@ -661,6 +662,17 @@ static void check_holdout_task(struct task_struct *t, sched_show_task(t); } +static void rcu_tasks_pertask(struct task_struct *t, struct list_head *hop) +{ + if (t != current && READ_ONCE(t->on_rq) && + !is_idle_task(t)) { + get_task_struct(t); + t->rcu_tasks_nvcsw = READ_ONCE(t->nvcsw); + WRITE_ONCE(t->rcu_tasks_holdout, true); + list_add(&t->rcu_tasks_holdout_list, hop); + } +} + /* RCU-tasks kthread that detects grace periods and invokes callbacks. */ static int __noreturn rcu_tasks_kthread(void *arg) { @@ -726,14 +738,7 @@ static int __noreturn rcu_tasks_kthread(void *arg) */ rcu_read_lock(); for_each_process_thread(g, t) { - if (t != current && READ_ONCE(t->on_rq) && - !is_idle_task(t)) { - get_task_struct(t); - t->rcu_tasks_nvcsw = READ_ONCE(t->nvcsw); - WRITE_ONCE(t->rcu_tasks_holdout, true); - list_add(&t->rcu_tasks_holdout_list, - &rcu_tasks_holdouts); - } + rcu_tasks_pertask(t, &rcu_tasks_holdouts); } rcu_read_unlock(); @@ -744,8 +749,12 @@ static int __noreturn rcu_tasks_kthread(void *arg) * where they have disabled preemption, allowing the * later synchronize_sched() to finish the job. */ - synchronize_srcu(&tasks_rcu_exit_srcu); - + raw_spin_lock_irqsave(&rtp_exit_list_lock, flags); + list_for_each_entry(t, &rtp_exit_list, rcu_tasks_exit_list) { + if (list_empty(&t->rcu_tasks_holdout_list)) + rcu_tasks_pertask(t, &rcu_tasks_holdouts); + } + raw_spin_unlock_irqrestore(&rtp_exit_list_lock, flags); /* * Each pass through the following loop scans the list * of holdout tasks, removing any that are no longer @@ -802,8 +811,7 @@ static int __noreturn rcu_tasks_kthread(void *arg) * * In addition, this synchronize_sched() waits for exiting * tasks to complete their final preempt_disable() region - * of execution, cleaning up after the synchronize_srcu() - * above. + * of execution. */ synchronize_sched(); @@ -835,20 +843,39 @@ static int __init rcu_spawn_tasks_kthread(void) } core_initcall(rcu_spawn_tasks_kthread); -/* Do the srcu_read_lock() for the above synchronize_srcu(). */ +/* + * Protect against tasklist scan blind spot while the task is exiting and + * may be removed from the tasklist. Do this by adding the task to yet + * another list. + */ void exit_tasks_rcu_start(void) { + unsigned long flags; + struct task_struct *t = current; + + WARN_ON_ONCE(!list_empty(&t->rcu_tasks_exit_list)); + get_task_struct(t); preempt_disable(); - current->rcu_tasks_idx = __srcu_read_lock(&tasks_rcu_exit_srcu); + raw_spin_lock_irqsave(&rtp_exit_list_lock, flags); + list_add(&t->rcu_tasks_exit_list, &rtp_exit_list); + raw_spin_unlock_irqrestore(&rtp_exit_list_lock, flags); preempt_enable(); } -/* Do the srcu_read_unlock() for the above synchronize_srcu(). */ +/* + * Remove the task from the "yet another list" because do_exit() is now + * non-preemptible, allowing synchronize_rcu() to wait beyond this point. + */ void exit_tasks_rcu_finish(void) { - preempt_disable(); - __srcu_read_unlock(&tasks_rcu_exit_srcu, current->rcu_tasks_idx); - preempt_enable(); + unsigned long flags; + struct task_struct *t = current; + + WARN_ON_ONCE(list_empty(&t->rcu_tasks_exit_list)); + raw_spin_lock_irqsave(&rtp_exit_list_lock, flags); + list_del_init(&t->rcu_tasks_exit_list); + raw_spin_unlock_irqrestore(&rtp_exit_list_lock, flags); + put_task_struct(t); } #endif /* #ifdef CONFIG_TASKS_RCU */ -- 2.34.1

2 1

[PATCH openEuler-1.0-LTS] [Backport] rcu-tasks: Eliminate deadlocks involving do_exit() and RCU tasks
by Liu Chuang 11 Apr '24

11 Apr '24

From: "Paul E. McKenney" <paulmck(a)kernel.org> maillist inclusion category: bugfix bugzilla: 189584 Reference: https://lore.kernel.org/all/20240207110846.25168-1-qiang.zhang1211@gmail.co… -------------------------------- commit bc31e6cb27a9334140ff2f0a209d59b08bc0bc8c upstream. Holding a mutex across synchronize_rcu_tasks() and acquiring that same mutex in code called from do_exit() after its call to exit_tasks_rcu_start() but before its call to exit_tasks_rcu_stop() results in deadlock. This is by design, because tasks that are far enough into do_exit() are no longer present on the tasks list, making it a bit difficult for RCU Tasks to find them, let alone wait on them to do a voluntary context switch. However, such deadlocks are becoming more frequent. In addition, lockdep currently does not detect such deadlocks and they can be difficult to reproduce. In addition, if a task voluntarily context switches during that time (for example, if it blocks acquiring a mutex), then this task is in an RCU Tasks quiescent state. And with some adjustments, RCU Tasks could just as well take advantage of that fact. This commit therefore eliminates these deadlock by replacing the SRCU-based wait for do_exit() completion with per-CPU lists of tasks currently exiting. A given task will be on one of these per-CPU lists for the same period of time that this task would previously have been in the previous SRCU read-side critical section. These lists enable RCU Tasks to find the tasks that have already been removed from the tasks list, but that must nevertheless be waited upon. The RCU Tasks grace period gathers any of these do_exit() tasks that it must wait on, and adds them to the list of holdouts. Per-CPU locking and get_task_struct() are used to synchronize addition to and removal from these lists. Link: https://lore.kernel.org/all/20240118021842.290665-1-chenzhongjin@huawei.com/ Reported-by: Chen Zhongjin <chenzhongjin(a)huawei.com> Signed-off-by: Paul E. McKenney <paulmck(a)kernel.org> Signed-off-by: Zqiang <qiang.zhang1211(a)gmail.com> --- include/linux/sched.h | 1 + init/init_task.c | 1 + kernel/fork.c | 1 + kernel/rcu/update.c | 65 ++++++++++++++++++++++++++++++------------- 4 files changed, 49 insertions(+), 19 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 8fd8c5b7cdc6..2dff665cc33a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -705,6 +705,7 @@ struct task_struct { u8 rcu_tasks_idx; int rcu_tasks_idle_cpu; struct list_head rcu_tasks_holdout_list; + struct list_head rcu_tasks_exit_list; #endif /* #ifdef CONFIG_TASKS_RCU */ struct sched_info sched_info; diff --git a/init/init_task.c b/init/init_task.c index b312a045f4b9..4bc8502d33d3 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -139,6 +139,7 @@ struct task_struct init_task .rcu_tasks_holdout = false, .rcu_tasks_holdout_list = LIST_HEAD_INIT(init_task.rcu_tasks_holdout_list), .rcu_tasks_idle_cpu = -1, + .rcu_tasks_exit_list = LIST_HEAD_INIT(init_task.rcu_tasks_exit_list), #endif #ifdef CONFIG_CPUSETS .mems_allowed_seq = SEQCNT_ZERO(init_task.mems_allowed_seq), diff --git a/kernel/fork.c b/kernel/fork.c index bfc4534ff116..8c96c517e09e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1711,6 +1711,7 @@ static inline void rcu_copy_process(struct task_struct *p) p->rcu_tasks_holdout = false; INIT_LIST_HEAD(&p->rcu_tasks_holdout_list); p->rcu_tasks_idle_cpu = -1; + INIT_LIST_HEAD(&p->rcu_tasks_exit_list); #endif /* #ifdef CONFIG_TASKS_RCU */ } diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 759ea6881a58..af9a43172d0e 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -527,7 +527,8 @@ static DECLARE_WAIT_QUEUE_HEAD(rcu_tasks_cbs_wq); static DEFINE_RAW_SPINLOCK(rcu_tasks_cbs_lock); /* Track exiting tasks in order to allow them to be waited for. */ -DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu); +static LIST_HEAD(rtp_exit_list); +static DEFINE_RAW_SPINLOCK(rtp_exit_list_lock); /* Control stall timeouts. Disable with <= 0, otherwise jiffies till stall. */ #define RCU_TASK_STALL_TIMEOUT (HZ * 60 * 10) @@ -661,6 +662,17 @@ static void check_holdout_task(struct task_struct *t, sched_show_task(t); } +static void rcu_tasks_pertask(struct task_struct *t, struct list_head *hop) +{ + if (t != current && READ_ONCE(t->on_rq) && + !is_idle_task(t)) { + get_task_struct(t); + t->rcu_tasks_nvcsw = READ_ONCE(t->nvcsw); + WRITE_ONCE(t->rcu_tasks_holdout, true); + list_add(&t->rcu_tasks_holdout_list, hop); + } +} + /* RCU-tasks kthread that detects grace periods and invokes callbacks. */ static int __noreturn rcu_tasks_kthread(void *arg) { @@ -726,14 +738,7 @@ static int __noreturn rcu_tasks_kthread(void *arg) */ rcu_read_lock(); for_each_process_thread(g, t) { - if (t != current && READ_ONCE(t->on_rq) && - !is_idle_task(t)) { - get_task_struct(t); - t->rcu_tasks_nvcsw = READ_ONCE(t->nvcsw); - WRITE_ONCE(t->rcu_tasks_holdout, true); - list_add(&t->rcu_tasks_holdout_list, - &rcu_tasks_holdouts); - } + rcu_tasks_pertask(t, &rcu_tasks_holdouts); } rcu_read_unlock(); @@ -744,8 +749,12 @@ static int __noreturn rcu_tasks_kthread(void *arg) * where they have disabled preemption, allowing the * later synchronize_sched() to finish the job. */ - synchronize_srcu(&tasks_rcu_exit_srcu); - + raw_spin_lock_irqsave(&rtp_exit_list_lock, flags); + list_for_each_entry(t, &rtp_exit_list, rcu_tasks_exit_list) { + if (list_empty(&t->rcu_tasks_holdout_list)) + rcu_tasks_pertask(t, &rcu_tasks_holdouts); + } + raw_spin_unlock_irqrestore(&rtp_exit_list_lock, flags); /* * Each pass through the following loop scans the list * of holdout tasks, removing any that are no longer @@ -802,8 +811,7 @@ static int __noreturn rcu_tasks_kthread(void *arg) * * In addition, this synchronize_sched() waits for exiting * tasks to complete their final preempt_disable() region - * of execution, cleaning up after the synchronize_srcu() - * above. + * of execution. */ synchronize_sched(); @@ -835,20 +843,39 @@ static int __init rcu_spawn_tasks_kthread(void) } core_initcall(rcu_spawn_tasks_kthread); -/* Do the srcu_read_lock() for the above synchronize_srcu(). */ +/* + * Protect against tasklist scan blind spot while the task is exiting and + * may be removed from the tasklist. Do this by adding the task to yet + * another list. + */ void exit_tasks_rcu_start(void) { + unsigned long flags; + struct task_struct *t = current; + + WARN_ON_ONCE(!list_empty(&t->rcu_tasks_exit_list)); + get_task_struct(t); preempt_disable(); - current->rcu_tasks_idx = __srcu_read_lock(&tasks_rcu_exit_srcu); + raw_spin_lock_irqsave(&rtp_exit_list_lock, flags); + list_add(&t->rcu_tasks_exit_list, &rtp_exit_list); + raw_spin_unlock_irqrestore(&rtp_exit_list_lock, flags); preempt_enable(); } -/* Do the srcu_read_unlock() for the above synchronize_srcu(). */ +/* + * Remove the task from the "yet another list" because do_exit() is now + * non-preemptible, allowing synchronize_rcu() to wait beyond this point. + */ void exit_tasks_rcu_finish(void) { - preempt_disable(); - __srcu_read_unlock(&tasks_rcu_exit_srcu, current->rcu_tasks_idx); - preempt_enable(); + unsigned long flags; + struct task_struct *t = current; + + WARN_ON_ONCE(list_empty(&t->rcu_tasks_exit_list)); + raw_spin_lock_irqsave(&rtp_exit_list_lock, flags); + list_del_init(&t->rcu_tasks_exit_list); + raw_spin_unlock_irqrestore(&rtp_exit_list_lock, flags); + put_task_struct(t); } #endif /* #ifdef CONFIG_TASKS_RCU */ -- 2.34.1

2 1

[PATCH OLK-5.10] net/sched: act_mirred: use the backlog for mirred ingress
by Zhengchao Shao 11 Apr '24

11 Apr '24

From: Jakub Kicinski <kuba(a)kernel.org> mainline inclusion from mainline-v6.8-rc6 commit 52f671db18823089a02f07efc04efdb2272ddc17 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2LT CVE: CVE-2024-26740 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress") hangs our testing VMs every 10 or so runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by lockdep. The problem as previously described by Davide (see Link) is that if we reverse flow of traffic with the redirect (egress -> ingress) we may reach the same socket which generated the packet. And we may still be holding its socket lock. The common solution to such deadlocks is to put the packet in the Rx backlog, rather than run the Rx path inline. Do that for all egress -> ingress reversals, not just once we started to nest mirred calls. In the past there was a concern that the backlog indirection will lead to loss of error reporting / less accurate stats. But the current workaround does not seem to address the issue. Fixes: 53592b364001 ("net/sched: act_mirred: Implement ingress actions") Cc: Marcelo Ricardo Leitner <marcelo.leitner(a)gmail.com> Suggested-by: Davide Caratti <dcaratti(a)redhat.com> Link: https://lore.kernel.org/netdev/33dc43f587ec1388ba456b4915c75f02a8aae226.166… Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> Acked-by: Jamal Hadi Salim <jhs(a)mojatatu.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Conflicts: net/sched/act_mirred.c Signed-off-by: Zhengchao Shao <shaozhengchao(a)huawei.com> --- net/sched/act_mirred.c | 14 +++++--------- .../testing/selftests/net/forwarding/tc_actions.sh | 3 --- 2 files changed, 5 insertions(+), 12 deletions(-) diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index 91a19460cb57..66c9f356a876 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -206,18 +206,14 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla, return err; } -static bool is_mirred_nested(void) -{ - return unlikely(__this_cpu_read(mirred_nest_level) > 1); -} - -static int tcf_mirred_forward(bool want_ingress, struct sk_buff *skb) +static int +tcf_mirred_forward(bool at_ingress, bool want_ingress, struct sk_buff *skb) { int err; if (!want_ingress) err = dev_queue_xmit(skb); - else if (is_mirred_nested()) + else if (!at_ingress) err = netif_rx(skb); else err = netif_receive_skb(skb); @@ -314,7 +310,7 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, /* let's the caller reinsert the packet, if possible */ if (use_reinsert) { res->ingress = want_ingress; - err = tcf_mirred_forward(res->ingress, skb); + err = tcf_mirred_forward(at_ingress, res->ingress, skb); if (err) tcf_action_inc_overlimit_qstats(&m->common); __this_cpu_dec(mirred_nest_level); @@ -322,7 +318,7 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, } } - err = tcf_mirred_forward(want_ingress, skb2); + err = tcf_mirred_forward(at_ingress, want_ingress, skb2); if (err) { out: tcf_action_inc_overlimit_qstats(&m->common); diff --git a/tools/testing/selftests/net/forwarding/tc_actions.sh b/tools/testing/selftests/net/forwarding/tc_actions.sh index e396e24d30e0..d6614faf9fe3 100755 --- a/tools/testing/selftests/net/forwarding/tc_actions.sh +++ b/tools/testing/selftests/net/forwarding/tc_actions.sh @@ -188,9 +188,6 @@ mirred_egress_to_ingress_tcp_test() check_err $? "didn't mirred redirect ICMP" tc_check_packets "dev $h1 ingress" 102 10 check_err $? "didn't drop mirred ICMP" - local overlimits=$(tc_rule_stats_get ${h1} 101 egress .overlimits) - test ${overlimits} = 10 - check_err $? "wrong overlimits, expected 10 got ${overlimits}" tc filter del dev $h1 egress protocol ip pref 100 handle 100 flower tc filter del dev $h1 egress protocol ip pref 101 handle 101 flower -- 2.34.1

2 1

[PATCH] net/sched: act_mirred: use the backlog for mirred ingress
by Zhengchao Shao 11 Apr '24

11 Apr '24

From: Jakub Kicinski <kuba(a)kernel.org> mainline inclusion from mainline-v6.8-rc6 commit 52f671db18823089a02f07efc04efdb2272ddc17 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2LT CVE: CVE-2024-26740 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress") hangs our testing VMs every 10 or so runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by lockdep. The problem as previously described by Davide (see Link) is that if we reverse flow of traffic with the redirect (egress -> ingress) we may reach the same socket which generated the packet. And we may still be holding its socket lock. The common solution to such deadlocks is to put the packet in the Rx backlog, rather than run the Rx path inline. Do that for all egress -> ingress reversals, not just once we started to nest mirred calls. In the past there was a concern that the backlog indirection will lead to loss of error reporting / less accurate stats. But the current workaround does not seem to address the issue. Fixes: 53592b364001 ("net/sched: act_mirred: Implement ingress actions") Cc: Marcelo Ricardo Leitner <marcelo.leitner(a)gmail.com> Suggested-by: Davide Caratti <dcaratti(a)redhat.com> Link: https://lore.kernel.org/netdev/33dc43f587ec1388ba456b4915c75f02a8aae226.166… Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> Acked-by: Jamal Hadi Salim <jhs(a)mojatatu.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Conflicts: net/sched/act_mirred.c Signed-off-by: Zhengchao Shao <shaozhengchao(a)huawei.com> --- net/sched/act_mirred.c | 15 ++++++--------- .../selftests/net/forwarding/tc_actions.sh | 3 --- 2 files changed, 6 insertions(+), 12 deletions(-) diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index febf06b8bbdf..336db2c938b5 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -197,18 +197,14 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla, return ret; } -static bool is_mirred_nested(void) -{ - return unlikely(__this_cpu_read(mirred_rec_level) > 1); -} - -static int tcf_mirred_forward(bool want_ingress, struct sk_buff *skb) +static int +tcf_mirred_forward(bool at_ingress, bool want_ingress, struct sk_buff *skb) { int err; if (!want_ingress) err = dev_queue_xmit(skb); - else if (is_mirred_nested()) + else if (!at_ingress) err = netif_rx(skb); else err = netif_receive_skb(skb); @@ -300,14 +296,15 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, if (use_reinsert) { res->ingress = want_ingress; res->qstats = this_cpu_ptr(m->common.cpu_qstats); - if (tcf_mirred_forward(want_ingress, skb) && res->qstats) + if (tcf_mirred_forward(skb_at_tc_ingress(skb), want_ingress, skb) + && res->qstats) qstats_overlimit_inc(res->qstats); __this_cpu_dec(mirred_rec_level); return TC_ACT_CONSUMED; } } - err = tcf_mirred_forward(want_ingress, skb2); + err = tcf_mirred_forward(skb_at_tc_ingress(skb), want_ingress, skb2); if (err) { out: qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats)); diff --git a/tools/testing/selftests/net/forwarding/tc_actions.sh b/tools/testing/selftests/net/forwarding/tc_actions.sh index aaa1ea10ac83..221a023ee5d6 100755 --- a/tools/testing/selftests/net/forwarding/tc_actions.sh +++ b/tools/testing/selftests/net/forwarding/tc_actions.sh @@ -183,9 +183,6 @@ mirred_egress_to_ingress_tcp_test() check_err $? "didn't mirred redirect ICMP" tc_check_packets "dev $h1 ingress" 102 10 check_err $? "didn't drop mirred ICMP" - local overlimits=$(tc_rule_stats_get ${h1} 101 egress .overlimits) - test ${overlimits} = 10 - check_err $? "wrong overlimits, expected 10 got ${overlimits}" tc filter del dev $h1 egress protocol ip pref 100 handle 100 flower tc filter del dev $h1 egress protocol ip pref 101 handle 101 flower -- 2.34.1

1 0

[PATCH openEuler-1.0-LTS] net/sched: act_mirred: use the backlog for mirred ingress
by Zhengchao Shao 11 Apr '24

11 Apr '24

From: Jakub Kicinski <kuba(a)kernel.org> mainline inclusion from mainline-v6.8-rc6 commit 52f671db18823089a02f07efc04efdb2272ddc17 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2LT CVE: CVE-2024-26740 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- The test Davide added in commit ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress") hangs our testing VMs every 10 or so runs, with the familiar tcp_v4_rcv -> tcp_v4_rcv deadlock reported by lockdep. The problem as previously described by Davide (see Link) is that if we reverse flow of traffic with the redirect (egress -> ingress) we may reach the same socket which generated the packet. And we may still be holding its socket lock. The common solution to such deadlocks is to put the packet in the Rx backlog, rather than run the Rx path inline. Do that for all egress -> ingress reversals, not just once we started to nest mirred calls. In the past there was a concern that the backlog indirection will lead to loss of error reporting / less accurate stats. But the current workaround does not seem to address the issue. Fixes: 53592b364001 ("net/sched: act_mirred: Implement ingress actions") Cc: Marcelo Ricardo Leitner <marcelo.leitner(a)gmail.com> Suggested-by: Davide Caratti <dcaratti(a)redhat.com> Link: https://lore.kernel.org/netdev/33dc43f587ec1388ba456b4915c75f02a8aae226.166… Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> Acked-by: Jamal Hadi Salim <jhs(a)mojatatu.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Conflicts: net/sched/act_mirred.c Signed-off-by: Zhengchao Shao <shaozhengchao(a)huawei.com> --- net/sched/act_mirred.c | 15 ++++++--------- .../selftests/net/forwarding/tc_actions.sh | 3 --- 2 files changed, 6 insertions(+), 12 deletions(-) diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index febf06b8bbdf..336db2c938b5 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -197,18 +197,14 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla, return ret; } -static bool is_mirred_nested(void) -{ - return unlikely(__this_cpu_read(mirred_rec_level) > 1); -} - -static int tcf_mirred_forward(bool want_ingress, struct sk_buff *skb) +static int +tcf_mirred_forward(bool at_ingress, bool want_ingress, struct sk_buff *skb) { int err; if (!want_ingress) err = dev_queue_xmit(skb); - else if (is_mirred_nested()) + else if (!at_ingress) err = netif_rx(skb); else err = netif_receive_skb(skb); @@ -300,14 +296,15 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, if (use_reinsert) { res->ingress = want_ingress; res->qstats = this_cpu_ptr(m->common.cpu_qstats); - if (tcf_mirred_forward(want_ingress, skb) && res->qstats) + if (tcf_mirred_forward(skb_at_tc_ingress(skb), want_ingress, skb) + && res->qstats) qstats_overlimit_inc(res->qstats); __this_cpu_dec(mirred_rec_level); return TC_ACT_CONSUMED; } } - err = tcf_mirred_forward(want_ingress, skb2); + err = tcf_mirred_forward(skb_at_tc_ingress(skb), want_ingress, skb2); if (err) { out: qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats)); diff --git a/tools/testing/selftests/net/forwarding/tc_actions.sh b/tools/testing/selftests/net/forwarding/tc_actions.sh index aaa1ea10ac83..221a023ee5d6 100755 --- a/tools/testing/selftests/net/forwarding/tc_actions.sh +++ b/tools/testing/selftests/net/forwarding/tc_actions.sh @@ -183,9 +183,6 @@ mirred_egress_to_ingress_tcp_test() check_err $? "didn't mirred redirect ICMP" tc_check_packets "dev $h1 ingress" 102 10 check_err $? "didn't drop mirred ICMP" - local overlimits=$(tc_rule_stats_get ${h1} 101 egress .overlimits) - test ${overlimits} = 10 - check_err $? "wrong overlimits, expected 10 got ${overlimits}" tc filter del dev $h1 egress protocol ip pref 100 handle 100 flower tc filter del dev $h1 egress protocol ip pref 101 handle 101 flower -- 2.34.1

2 1

[PATCH OLK-5.10 v2] IB/hfi1: Fix sdma.h tx->num_descs off-by-one error
by Liu Jian 11 Apr '24

11 Apr '24

From: Daniel Vacek <neelx(a)redhat.com> stable inclusion from stable-v5.10.211 commit 3f38d22e645e2e994979426ea5a35186102ff3c2 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E2Y3 CVE: CVE-2024-26766 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… --------------------------- commit e6f57c6881916df39db7d95981a8ad2b9c3458d6 upstream. Unfortunately the commit `fd8958efe877` introduced another error causing the `descs` array to overflow. This reults in further crashes easily reproducible by `sendmsg` system call. [ 1080.836473] general protection fault, probably for non-canonical address 0x400300015528b00a: 0000 [#1] PREEMPT SMP PTI [ 1080.869326] RIP: 0010:hfi1_ipoib_build_ib_tx_headers.constprop.0+0xe1/0x2b0 [hfi1] ... [ 1080.974535] Call Trace: [ 1080.976990] <TASK> [ 1081.021929] hfi1_ipoib_send_dma_common+0x7a/0x2e0 [hfi1] [ 1081.027364] hfi1_ipoib_send_dma_list+0x62/0x270 [hfi1] [ 1081.032633] hfi1_ipoib_send+0x112/0x300 [hfi1] [ 1081.042001] ipoib_start_xmit+0x2a9/0x2d0 [ib_ipoib] [ 1081.046978] dev_hard_start_xmit+0xc4/0x210 ... [ 1081.148347] __sys_sendmsg+0x59/0xa0 crash> ipoib_txreq 0xffff9cfeba229f00 struct ipoib_txreq { txreq = { list = { next = 0xffff9cfeba229f00, prev = 0xffff9cfeba229f00 }, descp = 0xffff9cfeba229f40, coalesce_buf = 0x0, wait = 0xffff9cfea4e69a48, complete = 0xffffffffc0fe0760 <hfi1_ipoib_sdma_complete>, packet_len = 0x46d, tlen = 0x0, num_desc = 0x0, desc_limit = 0x6, next_descq_idx = 0x45c, coalesce_idx = 0x0, flags = 0x0, descs = {{ qw = {0x8024000120dffb00, 0x4} # SDMA_DESC0_FIRST_DESC_FLAG (bit 63) }, { qw = { 0x3800014231b108, 0x4} }, { qw = { 0x310000e4ee0fcf0, 0x8} }, { qw = { 0x3000012e9f8000, 0x8} }, { qw = { 0x59000dfb9d0000, 0x8} }, { qw = { 0x78000e02e40000, 0x8} }} }, sdma_hdr = 0x400300015528b000, <<< invalid pointer in the tx request structure sdma_status = 0x0, SDMA_DESC0_LAST_DESC_FLAG (bit 62) complete = 0x0, priv = 0x0, txq = 0xffff9cfea4e69880, skb = 0xffff9d099809f400 } If an SDMA send consists of exactly 6 descriptors and requires dword padding (in the 7th descriptor), the sdma_txreq descriptor array is not properly expanded and the packet will overflow into the container structure. This results in a panic when the send completion runs. The exact panic varies depending on what elements of the container structure get corrupted. The fix is to use the correct expression in _pad_sdma_tx_descs() to test the need to expand the descriptor array. With this patch the crashes are no longer reproducible and the machine is stable. Fixes: fd8958efe877 ("IB/hfi1: Fix sdma.h tx->num_descs off-by-one errors") Cc: stable(a)vger.kernel.org Reported-by: Mats Kronberg <kronberg(a)nsc.liu.se> Tested-by: Mats Kronberg <kronberg(a)nsc.liu.se> Signed-off-by: Daniel Vacek <neelx(a)redhat.com> Link: https://lore.kernel.org/r/20240201081009.1109442-1-neelx@redhat.com Signed-off-by: Leon Romanovsky <leon(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> [Change commit log: "--" to "...". Otherwise openuler mail2pr ci-robot won't work.] Signed-off-by: Liu Jian <liujian56(a)huawei.com> --- v1->v2: change commit log. drivers/infiniband/hw/hfi1/sdma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c index 2dc97de434a5..68a8557e9a7c 100644 --- a/drivers/infiniband/hw/hfi1/sdma.c +++ b/drivers/infiniband/hw/hfi1/sdma.c @@ -3200,7 +3200,7 @@ int _pad_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx) { int rval = 0; - if ((unlikely(tx->num_desc + 1 == tx->desc_limit))) { + if ((unlikely(tx->num_desc == tx->desc_limit))) { rval = _extend_sdma_tx_descs(dd, tx); if (rval) { __sdma_txclean(dd, tx); -- 2.34.1

2 1