In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix use after free in iucv_sock_close() iucv_sever_path() is called from process context and from bh context. iucv->path is used as indicator whether somebody else is taking care of severing the path (or it is already removed / never existed). This needs to be done with atomic compare and swap, otherwise there is a small window where iucv_sock_close() will try to work with a path that has already been severed and freed by iucv_callback_connrej() called by iucv_tasklet_fn(). Example: [452744.123844] Call Trace: [452744.123845] ([<0000001e87f03880>] 0x1e87f03880) [452744.123966] [<00000000d593001e>] iucv_path_sever+0x96/0x138 [452744.124330] [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv] [452744.124336] [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv] [452744.124341] [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv] [452744.124345] [<00000000d574794e>] __sock_release+0x5e/0x…