Brian Norris <briannorris@xxxxxxxxxxxx> writes: > In general, it's helpful to use the same code for device removal as for > device reset, as this tends to have fewer bugs. Let's move the wiphy > unregistration code into the common reset and removal code. > > In particular, it's very hard to properly handle the reset sequence when > something fails. Currently, if mwifiex_reinit_sw() fails, we've failed > to unregister the associated wiphy, and so running something as simple > as "iw phy" can trigger an OOPS, as the wiphy still has hooks back into > freed mwifiex data structures. For example, KASAN complained: > > [... see reset fail for other reasons ...] > [ 1184.821158] mwifiex_pcie 0000:01:00.0: info: dnld wifi firmware from 174948 bytes > [ 1186.870914] mwifiex_pcie 0000:01:00.0: info: FW download over, size 608396 bytes > [ 1187.685990] mwifiex_pcie 0000:01:00.0: WLAN FW is active > [ 1187.692673] mwifiex_pcie 0000:01:00.0: cmd_wait_q terminated: -512 > [ 1187.699075] mwifiex_pcie 0000:01:00.0: info: _mwifiex_fw_dpc: unregister device > [ 1187.713476] mwifiex: Failed to bring up adapter: -5 > [ 1187.718644] mwifiex_pcie 0000:01:00.0: reinit failed: -5 > > [... run `iw phy` ...] > [ 1212.902419] ================================================================== > [ 1212.909806] BUG: KASAN: use-after-free in mwifiex_cfg80211_get_antenna+0x54/0xfc [mwifiex] at addr ffffffc0ad1a8028 > [ 1212.920246] Read of size 1 by task iw/3127 > [...] > [ 1212.934946] page dumped because: kasan: bad access detected > [...] > [ 1212.950665] Call trace: > [ 1212.953148] [<ffffffc00020a69c>] dump_backtrace+0x0/0x190 > [ 1212.958572] [<ffffffc00020a96c>] show_stack+0x20/0x28 > [ 1212.963648] [<ffffffc0005ce18c>] dump_stack+0xa4/0xcc > [ 1212.968723] [<ffffffc0003c4430>] kasan_report+0x378/0x500 > [ 1212.974140] [<ffffffc0003c3358>] __asan_load1+0x44/0x4c > [ 1212.979462] [<ffffffbffc2e8360>] mwifiex_cfg80211_get_antenna+0x54/0xfc [mwifiex] > [ 1212.987131] [<ffffffbffc084fc4>] nl80211_send_wiphy+0x75c/0x2de0 [cfg80211] > [ 1212.994246] [<ffffffbffc094f60>] nl80211_dump_wiphy+0x32c/0x438 [cfg80211] > [ 1213.001149] [<ffffffc000ab6404>] genl_lock_dumpit+0x48/0x64 > [ 1213.006746] [<ffffffc000ab3474>] netlink_dump+0x178/0x398 > [ 1213.012171] [<ffffffc000ab3d18>] __netlink_dump_start+0x1bc/0x260 > [...] > > This all goes away if we just tear down the wiphy on the way down, and > set it back up if/when we bring the device back up. I don't know exactly what kind of reset this is about, but isn't this a quite intrusive solution? For example, phy name changes because of this? -- Kalle Valo