In the Linux kernel, the following vulnerability has been resolved: ASoC: dapm: Fix UAF for sndsocpcmruntime object When using kernel with the following extra config, - CONFIGKASAN=y - CONFIGKASANGENERIC=y - CONFIGKASANINLINE=y - CONFIGKASANVMALLOC=y - CONFIGFRAMEWARN=4096 kernel detects that sndpcmsuspendall() access a freed 'sndsocpcmruntime' object when the system is suspended, which leads to a use-after-free bug: [ 52.047746] BUG: KASAN: use-after-free in sndpcmsuspendall+0x1a8/0x270 [ 52.047765] Read of size 1 at addr ffff0000b9434d50 by task systemd-sleep/2330 [ 52.047785] Call trace: [ 52.047787] dumpbacktrace+0x0/0x3c0 [ 52.047794] showstack+0x34/0x50 [ 52.047797] dumpstacklvl+0x68/0x8c [ 52.047802] printaddressdescription.constprop.0+0x74/0x2c0 [ 52.047809] kasanreport+0x210/0x230 [ 52.047815] _asanreportload1noabort+0x3c/0x50 [ 52.047820] sndpcmsuspendall+0x1a8/0x270 [ 52.047824] sndsocsuspend+0x19c/0x4e0 The sndpcmsyncstop() has a NULL check on 'substream->runtime' before making any access. So we need to always set 'substream->runtime' to NULL everytime we kfree() it.