In the Linux kernel, the following vulnerability has been resolved: net: sched: cake: fix null pointer access issue when cakeinit() fails When the default qdisc is cake, if the qdisc of devqueue fails to be inited during mqprioinit(), cakereset() is invoked to clear resources. In this case, the tins is NULL, and it will cause gpf issue. The process is as follows: qdisccreatedflt() cakeinit() q->tins = kvcalloc(...) --->failed, q->tins is NULL ... qdiscput() ... cakereset() ... cakedequeueone() b = &q->tins[...] --->q->tins is NULL The following is the Call Trace information: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:cakedequeueone+0xc9/0x3c0 Call Trace: <TASK> cakereset+0xb1/0x140 qdiscreset+0xed/0x6f0 qdiscdestroy+0x82/0x4c0 qdiscput+0x9e/0xb0 qdisccreatedflt+0x2c3/0x4a0 mqprioinit+0xa71/0x1760 qdisccreate+0x3eb/0x1000 tcmodifyqdisc+0x408/0x1720 rtnetlinkrcvmsg+0x38e/0xac0 netlinkrcvskb+0x12d/0x3a0 netlinkunicast+0x4a2/0x740 netlinksendmsg+0x826/0xcc0 socksendmsg+0xc5/0x100 _syssendmsg+0x583/0x690 syssendmsg+0xe8/0x160 _syssendmsg+0xbf/0x160 dosyscall64+0x35/0x80 entrySYSCALL64afterhwframe+0x46/0xb0 RIP: 0033:0x7f89e5122d04 </TASK>