On Mon, 2024-09-16 at 03:03 -0600, Jens Axboe wrote: > On 9/16/24 2:35 AM, kerne test robot wrote: > > [ 155.627997][ T6168] BUG: KASAN: slab-out-of-bounds in > > io_sq_offload_create (arch/x86/include/asm/bitops.h:227 > > arch/x86/include/asm/bitops.h:239 include/asm- > > generic/bitops/instrumented-non-atomic.h:142 > > include/linux/cpumask.h:562 io_uring/sqpoll.c:469) > > [ 155.628787][ T6168] Read of size 8 at addr ffff888138ecf948 by > > task trinity-c3/6168 > > [ 155.629542][ T6168] > > [ 155.629806][ T6168] CPU: 1 UID: 4294967291 PID: 6168 Comm: > > trinity-c3 Not tainted 6.11.0-rc5-00027-gf011c9cf04c0 #1 > > 074b2dc9794d1910767b5e24d1a9cb7061a66647 > > [ 155.631255][ T6168] Hardware name: QEMU Standard PC (i440FX + > > PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 > > [ 155.632276][ T6168] Call Trace: > > [ 155.632627][ T6168] <TASK> > > [ 155.632952][ T6168] dump_stack_lvl (lib/dump_stack.c:122) > > [ 155.633418][ T6168] print_address_description+0x51/0x3a0 > > [ 155.634147][ T6168] ? io_sq_offload_create > > (arch/x86/include/asm/bitops.h:227 > > arch/x86/include/asm/bitops.h:239 include/asm- > > generic/bitops/instrumented-non-atomic.h:142 > > include/linux/cpumask.h:562 io_uring/sqpoll.c:469) > > [ 155.634671][ T6168] print_report (mm/kasan/report.c:489) > > [ 155.635119][ T6168] ? lock_acquired > > (include/trace/events/lock.h:85 kernel/locking/lockdep.c:6039) > > [ 155.635596][ T6168] ? kasan_addr_to_slab (include/linux/mm.h:1283 > > mm/kasan/../slab.h:206 mm/kasan/common.c:38) > > [ 155.636243][ T6168] ? io_sq_offload_create > > (arch/x86/include/asm/bitops.h:227 > > arch/x86/include/asm/bitops.h:239 include/asm- > > generic/bitops/instrumented-non-atomic.h:142 > > include/linux/cpumask.h:562 io_uring/sqpoll.c:469) > > [ 155.636890][ T6168] kasan_report (mm/kasan/report.c:603) > > [ 155.637320][ T6168] ? io_sq_offload_create > > (arch/x86/include/asm/bitops.h:227 > > arch/x86/include/asm/bitops.h:239 include/asm- > > generic/bitops/instrumented-non-atomic.h:142 > > include/linux/cpumask.h:562 io_uring/sqpoll.c:469) > > [ 155.637873][ T6168] kasan_check_range (mm/kasan/generic.c:183 > > mm/kasan/generic.c:189) > > [ 155.638384][ T6168] io_sq_offload_create > > (arch/x86/include/asm/bitops.h:227 > > arch/x86/include/asm/bitops.h:239 include/asm- > > generic/bitops/instrumented-non-atomic.h:142 > > include/linux/cpumask.h:562 io_uring/sqpoll.c:469) > > [ 155.638921][ T6168] ? __pfx_io_sq_offload_create > > (io_uring/sqpoll.c:413) > > [ 155.639501][ T6168] ? __lock_acquire > > (kernel/locking/lockdep.c:5142) > > [ 155.640040][ T6168] ? io_pages_map (include/linux/gfp.h:269 > > include/linux/gfp.h:296 include/linux/gfp.h:313 > > io_uring/memmap.c:28 io_uring/memmap.c:72) > > [ 155.640495][ T6168] ? io_allocate_scq_urings > > (io_uring/io_uring.c:3441) > > [ 155.641079][ T6168] io_uring_create (io_uring/io_uring.c:3606) > > [ 155.641591][ T6168] io_uring_setup (io_uring/io_uring.c:3715) > > [ 155.642185][ T6168] ? __pfx_io_uring_setup > > (io_uring/io_uring.c:3693) > > [ 155.642698][ T6168] ? do_int80_emulation > > (arch/x86/include/asm/irqflags.h:42 > > arch/x86/include/asm/irqflags.h:97 arch/x86/entry/common.c:251) > > [ 155.643206][ T6168] do_int80_emulation > > (arch/x86/entry/common.c:165 arch/x86/entry/common.c:253) > > [ 155.643675][ T6168] asm_int80_emulation > > (arch/x86/include/asm/idtentry.h:626) > > The fix for the cpusets dropped checking if the value was sane to > begin > with... I've fixed it up with the patch below. Thanks for fixing. While we are at it, I noticed that putting the cpumask on the stack is discouraged. We should better allocate it like in my other patches. Shall I send a fixup patch? Best regards, Felix > > commit 827e3ea024a4facf1d6c8969ae95de939890039e > Author: Jens Axboe <axboe@xxxxxxxxx> > Date: Mon Sep 16 02:58:06 2024 -0600 > > io_uring/sqpoll: retain test for whether the CPU is valid > > A recent commit ensured that SQPOLL cannot be setup with a CPU > that > isn't in the current tasks cpuset, but it also dropped testing > whether > the CPU is valid in the first place. Without that, if a task > passes in > a CPU value that is too high, the following KASAN splat can get > triggered: > > BUG: KASAN: stack-out-of-bounds in > io_sq_offload_create+0x858/0xaa4 > Read of size 8 at addr ffff800089bc7b90 by task wq-aff.t/1391 > > CPU: 4 UID: 1000 PID: 1391 Comm: wq-aff.t Not tainted 6.11.0-rc7- > 00227-g371c468f4db6 #7080 > Hardware name: linux,dummy-virt (DT) > Call trace: > dump_backtrace.part.0+0xcc/0xe0 > show_stack+0x14/0x1c > dump_stack_lvl+0x58/0x74 > print_report+0x16c/0x4c8 > kasan_report+0x9c/0xe4 > __asan_report_load8_noabort+0x1c/0x24 > io_sq_offload_create+0x858/0xaa4 > io_uring_setup+0x1394/0x17c4 > __arm64_sys_io_uring_setup+0x6c/0x180 > invoke_syscall+0x6c/0x260 > el0_svc_common.constprop.0+0x158/0x224 > do_el0_svc+0x3c/0x5c > el0_svc+0x34/0x70 > el0t_64_sync_handler+0x118/0x124 > el0t_64_sync+0x168/0x16c > > The buggy address belongs to stack of task wq-aff.t/1391 > and is located at offset 48 in frame: > io_sq_offload_create+0x0/0xaa4 > > This frame has 1 object: > [32, 40) 'allowed_mask' > > The buggy address belongs to the virtual mapping at > [ffff800089bc0000, ffff800089bc9000) created by: > kernel_clone+0x124/0x7e0 > > The buggy address belongs to the physical page: > page: refcount:1 mapcount:0 mapping:0000000000000000 > index:0xffff0000d740af80 pfn:0x11740a > memcg:ffff0000c2706f02 > flags: 0xbffe00000000000(node=0|zone=2|lastcpupid=0x1fff) > raw: 0bffe00000000000 0000000000000000 dead000000000122 > 0000000000000000 > raw: ffff0000d740af80 0000000000000000 00000001ffffffff > ffff0000c2706f02 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff800089bc7a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 > ffff800089bc7b00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 > f1 > >ffff800089bc7b80: 00 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 > 00 > ^ > ffff800089bc7c00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 > f1 > ffff800089bc7c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > f3 > > Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> > Closes: > https://lore.kernel.org/oe-lkp/202409161632.cbeeca0d-lkp@xxxxxxxxx > Fixes: f011c9cf04c0 ("io_uring/sqpoll: do not allow pinning > outside of cpuset") > Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> > > diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c > index 272df9d00f45..7adfcf6818ff 100644 > --- a/io_uring/sqpoll.c > +++ b/io_uring/sqpoll.c > @@ -465,6 +465,8 @@ __cold int io_sq_offload_create(struct > io_ring_ctx *ctx, > int cpu = p->sq_thread_cpu; > > ret = -EINVAL; > + if (cpu >= nr_cpu_ids || !cpu_online(cpu)) > + goto err_sqpoll; > cpuset_cpus_allowed(current, &allowed_mask); > if (!cpumask_test_cpu(cpu, &allowed_mask)) > goto err_sqpoll; > -- Siemens AG, Technology Linux Expert Center
