Messages in this thread | | | Date | Thu, 1 Sep 2022 21:25:27 +0200 | From | Francesco Dolcini <> | Subject | Re: possible circular locking in kernfs_remove_by_name_ns/devinet_ioctl linux 6.0-rc3 |
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On Thu, Sep 01, 2022 at 02:21:29PM +0200, Francesco Dolcini wrote: > [ 21.629186] ====================================================== > [ 21.635418] WARNING: possible circular locking dependency detected > [ 21.641646] 6.0.0-rc3 #7 Not tainted > [ 21.645256] ------------------------------------------------------ > [ 21.651480] connmand/542 is trying to acquire lock: > [ 21.656399] c2ce1d70 (kn->active#9){++++}-{0:0}, at: kernfs_remove_by_name_ns+0x50/0xa0 > [ 21.664516] > but task is already holding lock: > [ 21.670394] c17af6e0 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0xc8/0x870 > [ 21.677441] > which lock already depends on the new lock. ... > [ 21.945318] Chain exists of: > kn->active#9 --> udc_lock --> rtnl_mutex > > [ 21.954902] Possible unsafe locking scenario: > > [ 21.960865] CPU0 CPU1 > [ 21.965430] ---- ---- > [ 21.969994] lock(rtnl_mutex); > [ 21.973174] lock(udc_lock); > [ 21.978709] lock(rtnl_mutex); > [ 21.984419] lock(kn->active#9); > [ 21.987779] > *** DEADLOCK *** > > [ 21.993745] 1 lock held by connmand/542: > [ 21.997704] #0: c17af6e0 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0xc8/0x870 > [ 22.005191] ... > I have not tried to bisect this yet, just probing if someone has already > some idea on this.
Commit 2191c00855b0 ("USB: gadget: Fix use-after-free Read in usb_udc_uevent()") introduced this, see https://lore.kernel.org/all/20220901192204.GA2268599@francesco-nb.int.toradex.com/
Francesco
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