be408e65f5
The current implementation does not wait until srpt_release_channel() has finished and hence can trigger a use-after-free. Rework srpt_release_sport() such that it waits until srpt_release_channel() has finished. This patch fixes the following KASAN complaint: ================================================================== BUG: KASAN: use-after-free in srpt_free_ioctx.part.23+0x42/0x100 [ib_srpt] Read of size 8 at addr ffff888115c71100 by task kworker/4:3/807 CPU: 4 PID: 807 Comm: kworker/4:3 Not tainted 5.3.0-dbg+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Workqueue: events srpt_release_channel_work [ib_srpt] Call Trace: dump_stack+0x86/0xca print_address_description+0x74/0x32d __kasan_report.cold.6+0x1b/0x36 kasan_report+0x12/0x17 __asan_load8+0x54/0x90 srpt_free_ioctx.part.23+0x42/0x100 [ib_srpt] srpt_free_ioctx_ring.part.24+0x50/0x80 [ib_srpt] srpt_release_channel_work+0x2ad/0x390 [ib_srpt] process_one_work+0x51a/0xa60 worker_thread+0x67/0x5b0 kthread+0x1dc/0x200 ret_from_fork+0x24/0x30 Allocated by task 984: save_stack+0x21/0x90 __kasan_kmalloc.constprop.9+0xc7/0xd0 kasan_kmalloc+0x9/0x10 __kmalloc+0x153/0x370 srpt_add_one+0x4f/0x570 [ib_srpt] add_client_context+0x251/0x290 [ib_core] ib_register_client+0x1da/0x220 [ib_core] iblock_get_alignment_offset_lbas+0x6b/0x100 [target_core_iblock] do_one_initcall+0xcd/0x43a do_init_module+0x103/0x380 load_module+0x3b77/0x3eb0 __do_sys_finit_module+0x12d/0x1b0 __x64_sys_finit_module+0x43/0x50 do_syscall_64+0x6b/0x2d0 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 1128: save_stack+0x21/0x90 __kasan_slab_free+0x139/0x190 kasan_slab_free+0xe/0x10 slab_free_freelist_hook+0x67/0x1e0 kfree+0xcb/0x2a0 srpt_remove_one+0x569/0x5b0 [ib_srpt] remove_client_context+0x9a/0xe0 [ib_core] disable_device+0x106/0x1b0 [ib_core] __ib_unregister_device+0x5f/0xf0 [ib_core] ib_unregister_device_and_put+0x48/0x60 [ib_core] nldev_dellink+0x120/0x180 [ib_core] rdma_nl_rcv+0x287/0x480 [ib_core] netlink_unicast+0x2cc/0x370 netlink_sendmsg+0x3b1/0x630 __sys_sendto+0x1db/0x290 __x64_sys_sendto+0x80/0xa0 do_syscall_64+0x6b/0x2d0 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888115c71100 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 0 bytes inside of 4096-byte region [ffff888115c71100, ffff888115c72100) The buggy address belongs to the page: page:ffffea0004571c00 refcount:1 mapcount:0 mapping:ffff88811ac0de00 index:0xffff888115c70000 compound_mapcount: 0 flags: 0x2fff000000010200(slab|head) raw: 2fff000000010200 ffffea00045ac408 ffffea0004593208 ffff88811ac0de00 raw: ffff888115c70000 0000000000070002 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888115c71000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888115c71080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888115c71100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888115c71180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888115c71200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Link: https://lore.kernel.org/r/20190930231707.48259-14-bvanassche@acm.org Cc: Honggang LI <honli@redhat.com> Cc: Laurence Oberman <loberman@redhat.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.