In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/sched: reject IDR error pointers when deleting actions<\/p>\n
tcf_action_delete() drops the reference held by its lookup before calling
\ntcf_idr_delete_index() with the saved action index. An unlocked
\nclassifier can remove that action and reserve the same IDR slot with
\nERR_PTR(-EBUSY) in between.<\/p>\n
tcf_idr_delete_index() only checks the lookup result for NULL. It
\ntherefore treats the reservation as a tc_action and dereferences
\ntcfa_bindcnt. A hardware execution breakpoint was used to schedule the
\ninterleaving without changing the kernel source. KASAN reported this
\ndecoded trace:<\/p>\n
BUG: KASAN: null-ptr-deref in tca_action_gd+0x5b9\/0x1010
\n Read of size 4 at addr 0000000000000010 by task poc\/150
\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002
\n RIP: tca_action_gd+0x5c0\/0x1010:
\n arch_atomic_read at arch\/x86\/include\/asm\/atomic.h:23
\n raw_atomic_read at include\/linux\/atomic\/atomic-arch-fallback.h:457
\n atomic_read at include\/linux\/atomic\/atomic-instrumented.h:33
\n tcf_idr_delete_index at net\/sched\/act_api.c:766
\n tcf_action_delete at net\/sched\/act_api.c:1859
\n tcf_del_notify at net\/sched\/act_api.c:2014
\n tca_action_gd at net\/sched\/act_api.c:2064
\n R13: 0000000000000010 R15: fffffffffffffff0
\n Kernel panic – not syncing: Fatal exception<\/p>\n
R15 contains ERR_PTR(-EBUSY), and adding the tcfa_bindcnt offset produces
\nthe address in R13. With the guard applied, the same reproducer returned
\n-ENOENT without a KASAN report or panic. Treat error pointers as absent
\nand return -ENOENT.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
net\/sched: reject IDR error pointers when deleting actions<\/p>\n
tcf_action_delete() drops the reference held by its lookup before calli<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-34943","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/34943","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=34943"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=34943"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=34943"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}