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-rw-r--r--0005-cgroup-fix-css_task_iter-crash-on-CSS_TASK_ITER_PROC.patch114
1 files changed, 0 insertions, 114 deletions
diff --git a/0005-cgroup-fix-css_task_iter-crash-on-CSS_TASK_ITER_PROC.patch b/0005-cgroup-fix-css_task_iter-crash-on-CSS_TASK_ITER_PROC.patch
deleted file mode 100644
index 3090318aacb..00000000000
--- a/0005-cgroup-fix-css_task_iter-crash-on-CSS_TASK_ITER_PROC.patch
+++ /dev/null
@@ -1,114 +0,0 @@
-From eadda028a73a567edd8462ccd0e8c28e023cde28 Mon Sep 17 00:00:00 2001
-Message-Id: <eadda028a73a567edd8462ccd0e8c28e023cde28.1515173964.git.jan.steffens@gmail.com>
-In-Reply-To: <0b716bdb952b678d9bb5eb32198dbc82ec492df2.1515173964.git.jan.steffens@gmail.com>
-References: <0b716bdb952b678d9bb5eb32198dbc82ec492df2.1515173964.git.jan.steffens@gmail.com>
-From: Tejun Heo <tj@kernel.org>
-Date: Wed, 20 Dec 2017 07:09:19 -0800
-Subject: [PATCH 5/6] cgroup: fix css_task_iter crash on CSS_TASK_ITER_PROC
-
-While teaching css_task_iter to handle skipping over tasks which
-aren't group leaders, bc2fb7ed089f ("cgroup: add @flags to
-css_task_iter_start() and implement CSS_TASK_ITER_PROCS") introduced a
-silly bug.
-
-CSS_TASK_ITER_PROCS is implemented by repeating
-css_task_iter_advance() while the advanced cursor is pointing to a
-non-leader thread. However, the cursor variable, @l, wasn't updated
-when the iteration has to advance to the next css_set and the
-following repetition would operate on the terminal @l from the
-previous iteration which isn't pointing to a valid task leading to
-oopses like the following or infinite looping.
-
- BUG: unable to handle kernel NULL pointer dereference at 0000000000000254
- IP: __task_pid_nr_ns+0xc7/0xf0
- PGD 0 P4D 0
- Oops: 0000 [#1] SMP
- ...
- CPU: 2 PID: 1 Comm: systemd Not tainted 4.14.4-200.fc26.x86_64 #1
- Hardware name: System manufacturer System Product Name/PRIME B350M-A, BIOS 3203 11/09/2017
- task: ffff88c4baee8000 task.stack: ffff96d5c3158000
- RIP: 0010:__task_pid_nr_ns+0xc7/0xf0
- RSP: 0018:ffff96d5c315bd50 EFLAGS: 00010206
- RAX: 0000000000000000 RBX: ffff88c4b68c6000 RCX: 0000000000000250
- RDX: ffffffffa5e47960 RSI: 0000000000000000 RDI: ffff88c490f6ab00
- RBP: ffff96d5c315bd50 R08: 0000000000001000 R09: 0000000000000005
- R10: ffff88c4be006b80 R11: ffff88c42f1b8004 R12: ffff96d5c315bf18
- R13: ffff88c42d7dd200 R14: ffff88c490f6a510 R15: ffff88c4b68c6000
- FS: 00007f9446f8ea00(0000) GS:ffff88c4be680000(0000) knlGS:0000000000000000
- CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
- CR2: 0000000000000254 CR3: 00000007f956f000 CR4: 00000000003406e0
- Call Trace:
- cgroup_procs_show+0x19/0x30
- cgroup_seqfile_show+0x4c/0xb0
- kernfs_seq_show+0x21/0x30
- seq_read+0x2ec/0x3f0
- kernfs_fop_read+0x134/0x180
- __vfs_read+0x37/0x160
- ? security_file_permission+0x9b/0xc0
- vfs_read+0x8e/0x130
- SyS_read+0x55/0xc0
- entry_SYSCALL_64_fastpath+0x1a/0xa5
- RIP: 0033:0x7f94455f942d
- RSP: 002b:00007ffe81ba2d00 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
- RAX: ffffffffffffffda RBX: 00005574e2233f00 RCX: 00007f94455f942d
- RDX: 0000000000001000 RSI: 00005574e2321a90 RDI: 000000000000002b
- RBP: 0000000000000000 R08: 00005574e2321a90 R09: 00005574e231de60
- R10: 00007f94458c8b38 R11: 0000000000000293 R12: 00007f94458c8ae0
- R13: 00007ffe81ba3800 R14: 0000000000000000 R15: 00005574e2116560
- Code: 04 74 0e 89 f6 48 8d 04 76 48 8d 04 c5 f0 05 00 00 48 8b bf b8 05 00 00 48 01 c7 31 c0 48 8b 0f 48 85 c9 74 18 8b b2 30 08 00 00 <3b> 71 04 77 0d 48 c1 e6 05 48 01 f1 48 3b 51 38 74 09 5d c3 8b
- RIP: __task_pid_nr_ns+0xc7/0xf0 RSP: ffff96d5c315bd50
-
-Fix it by moving the initialization of the cursor below the repeat
-label. While at it, rename it to @next for readability.
-
-Signed-off-by: Tejun Heo <tj@kernel.org>
-Fixes: bc2fb7ed089f ("cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS")
-Cc: stable@vger.kernel.org # v4.14+
-Reported-by: Laura Abbott <labbott@redhat.com>
-Reported-by: Bronek Kozicki <brok@incorrekt.com>
-Reported-by: George Amanakis <gamanakis@gmail.com>
-Signed-off-by: Tejun Heo <tj@kernel.org>
----
- kernel/cgroup/cgroup.c | 14 ++++++--------
- 1 file changed, 6 insertions(+), 8 deletions(-)
-
-diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
-index 44857278eb8aa6a2..030e4286f14c715e 100644
---- a/kernel/cgroup/cgroup.c
-+++ b/kernel/cgroup/cgroup.c
-@@ -4059,26 +4059,24 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it)
-
- static void css_task_iter_advance(struct css_task_iter *it)
- {
-- struct list_head *l = it->task_pos;
-+ struct list_head *next;
-
- lockdep_assert_held(&css_set_lock);
-- WARN_ON_ONCE(!l);
--
- repeat:
- /*
- * Advance iterator to find next entry. cset->tasks is consumed
- * first and then ->mg_tasks. After ->mg_tasks, we move onto the
- * next cset.
- */
-- l = l->next;
-+ next = it->task_pos->next;
-
-- if (l == it->tasks_head)
-- l = it->mg_tasks_head->next;
-+ if (next == it->tasks_head)
-+ next = it->mg_tasks_head->next;
-
-- if (l == it->mg_tasks_head)
-+ if (next == it->mg_tasks_head)
- css_task_iter_advance_css_set(it);
- else
-- it->task_pos = l;
-+ it->task_pos = next;
-
- /* if PROCS, skip over tasks which aren't group leaders */
- if ((it->flags & CSS_TASK_ITER_PROCS) && it->task_pos &&
---
-2.15.1
-