On 4/3/19 9:49 AM, Will Deacon wrote: > On Wed, Apr 03, 2019 at 09:39:52AM -0600, Jens Axboe wrote: >> On 4/3/19 9:19 AM, Will Deacon wrote: >>> On Wed, Apr 03, 2019 at 07:49:26AM -0600, Jens Axboe wrote: >>>> On 4/3/19 5:11 AM, Will Deacon wrote: >>>>> will@autoplooker:~/liburing/test$ ./io_uring_register >>>>> RELIMIT_MEMLOCK: 67108864 (67108864) >>>>> [ 35.477875] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070 >>>>> [ 35.478969] Mem abort info: >>>>> [ 35.479296] ESR = 0x96000004 >>>>> [ 35.479785] Exception class = DABT (current EL), IL = 32 bits >>>>> [ 35.480528] SET = 0, FnV = 0 >>>>> [ 35.480980] EA = 0, S1PTW = 0 >>>>> [ 35.481345] Data abort info: >>>>> [ 35.481680] ISV = 0, ISS = 0x00000004 >>>>> [ 35.482267] CM = 0, WnR = 0 >>>>> [ 35.482618] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____) >>>>> [ 35.483486] [0000000000000070] pgd=0000000000000000 >>>>> [ 35.484041] Internal error: Oops: 96000004 [#1] PREEMPT SMP >>>>> [ 35.484788] Modules linked in: >>>>> [ 35.485311] CPU: 113 PID: 3973 Comm: io_uring_regist Not tainted 5.1.0-rc3-00012-g40b114779944 #1 >>>>> [ 35.486712] Hardware name: linux,dummy-virt (DT) >>>>> [ 35.487450] pstate: 20400005 (nzCv daif +PAN -UAO) >>>>> [ 35.488228] pc : link_pwq+0x10/0x60 >>>>> [ 35.488794] lr : apply_wqattrs_commit+0xe0/0x118 >>>>> [ 35.489550] sp : ffff000017e2bbc0 >>>> >>>> Huh, this looks odd, it's crashing inside the wq setup. >>> >>> Enabling KASAN seems to indicate a double-free, which may well be related. >> >> Does this help? > > Yes, thanks for the quick patch. Feel free to add: > > Reported-by: Will Deacon <will.deacon@xxxxxxx> > Tested-by: Will Deacon <will.deacon@xxxxxxx> > > if you spin a proper patch. Great, thanks for reporting/testing. -- Jens Axboe
