On Fri, May 27, 2022 at 05:36:51PM -0400, Alan Stern wrote: > On Fri, May 27, 2022 at 12:29:08PM -0700, syzbot wrote: > > Hello, > > > > syzbot has tested the proposed patch but the reproducer is still triggering an issue: > > WARNING in sysfs_create_file_ns > > > > really_probe: driver_sysfs_add(gadget.0) failed > > ------------[ cut here ]------------ > > WARNING: CPU: 0 PID: 2361 at fs/sysfs/file.c:351 sysfs_create_file_ns+0x131/0x1c0 fs/sysfs/file.c:351 > > Modules linked in: > > CPU: 0 PID: 2361 Comm: syz-executor.0 Not tainted 5.18.0-rc5-syzkaller-00157-g97fa5887cf28-dirty #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > RIP: 0010:sysfs_create_file_ns+0x131/0x1c0 fs/sysfs/file.c:351 > > Code: e9 03 80 3c 01 00 75 7f 8b 4c 24 38 4d 89 e9 48 89 ee 48 8b 7b 30 44 8b 44 24 48 e8 e9 fa ff ff 41 89 c5 eb 0d e8 cf 7c 9d ff <0f> 0b 41 bd ea ff ff ff e8 c2 7c 9d ff 48 b8 00 00 00 00 00 fc ff > > RSP: 0018:ffffc900028ffca0 EFLAGS: 00010293 > > Here's some extra detail, taken from the console log: > > [ 98.336685][ T2361] really_probe: driver_sysfs_add(gadget.0) failed > [ 98.336836][ T2360] sysfs: cannot create duplicate filename '/bus/gadget/drivers/dummy_udc' > [ 98.343498][ T2361] ------------[ cut here ]------------ > [ 98.352154][ T2360] CPU: 1 PID: 2360 Comm: syz-executor.0 Not tainted 5.18.0-rc5-syzkaller-00157-g97fa5887cf28-dirty #0 > [ 98.357802][ T2361] WARNING: CPU: 0 PID: 2361 at fs/sysfs/file.c:351 sysfs_create_file_ns+0x131/0x1c0 > > Simultaneous splats from two different threads trying to add drivers with > the same name suggests there might be a concurrency bug in the sysfs > filesystem. This sort of thing should be an error but it shouldn't bring > the kernel to its knees. It's not bringing anything down, it's just giving you a big fat warning that the developer did something wrong and it should be fixed. The kernel should keep working just fine after this. > Greg, do you know anyone who could take a look at this? I don't know much > about sysfs. It's not a sysfs thing, it's a "we should not register the same driver name multiple times" thing, so that subsystem needs to be fixed to make this always a unique name. thanks, greg k-h
