In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
blk-cgroup: save IRQ state in blkg_tryget_closest()<\/p>\n
bio_set_dev() associates the bio with a blkg through bio_associate_blkg().
\nIf the blkg lookup misses, blkg_tryget_closest() takes q->queue_lock with
\nspin_lock_irq() and releases it with spin_unlock_irq(), which
\nunconditionally enables local interrupts.<\/p>\n
Callers may call bio_set_dev() with interrupts already disabled, e.g.
\ndm-thin’s pool_map() does so while holding pool->lock taken with
\nspin_lock_irq(). The nested spin_unlock_irq() then enables interrupts
\nwhile pool->lock is still held, so an I\/O completion softirq can run on
\nthe same CPU, re-acquire pool->lock (thin_endio(), or overwrite_endio()
\n-> complete_mapping_preparation()) and deadlock. lockdep reports this
\nas inconsistent SOFTIRQ-ON-W to IN-SOFTIRQ-W usage.<\/p>\n
Commit 3a762de55b4e (“block: save irq state in blkg_lookup_create()”)
\nfixed the same problem while the lock lived in blkg_lookup_create(), but
\ncommit 9327a865e395 (“blk-cgroup: don’t nest queue_lock under rcu in
\nblkg_lookup_create()”) moved the locking into blkg_tryget_closest() and
\nreverted it to spin_lock_irq().<\/p>\n
Save and restore the caller’s IRQ state instead.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
blk-cgroup: save IRQ state in blkg_tryget_closest()<\/p>\n
bio_set_dev() associates the bio with a blkg through bio_associate_blkg().
\nIf <\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-41304","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/41304","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=41304"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41304"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41304"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}