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Avihai Horon fe454dc31e RDMA/ucma: Fix use-after-free bug in ucma_create_uevent
ucma_process_join() allocates struct ucma_multicast mc and frees it if an
error occurs during its run.  Specifically, if an error occurs in
copy_to_user(), a use-after-free might happen in the following scenario:

1. mc struct is allocated.
2. rdma_join_multicast() is called and succeeds. During its run,
   cma_iboe_join_multicast() enqueues a work that will later use the
   aforementioned mc struct.
3. copy_to_user() is called and fails.
4. mc struct is deallocated.
5. The work that was enqueued by cma_iboe_join_multicast() is run and
   calls ucma_create_uevent() which tries to access mc struct (which is
   freed by now).

Fix this bug by cancelling the work enqueued by cma_iboe_join_multicast().
Since cma_work_handler() frees struct cma_work, we don't use it in
cma_iboe_join_multicast() so we can safely cancel the work later.

The following syzkaller report revealed it:

   BUG: KASAN: use-after-free in ucma_create_uevent+0x2dd/0x;3f0 drivers/infiniband/core/ucma.c:272
   Read of size 8 at addr ffff88810b3ad110 by task kworker/u8:1/108

   CPU: 1 PID: 108 Comm: kworker/u8:1 Not tainted 5.10.0-rc6+ #257
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS   rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
   Workqueue: rdma_cm cma_work_handler
   Call Trace:
    __dump_stack lib/dump_stack.c:77 [inline]
    dump_stack+0xbe/0xf9 lib/dump_stack.c:118
    print_address_description.constprop.0+0x3e/0×60 mm/kasan/report.c:385
    __kasan_report mm/kasan/report.c:545 [inline]
    kasan_report.cold+0x1f/0×37 mm/kasan/report.c:562
    ucma_create_uevent+0x2dd/0×3f0 drivers/infiniband/core/ucma.c:272
    ucma_event_handler+0xb7/0×3c0 drivers/infiniband/core/ucma.c:349
    cma_cm_event_handler+0x5d/0×1c0 drivers/infiniband/core/cma.c:1977
    cma_work_handler+0xfa/0×190 drivers/infiniband/core/cma.c:2718
    process_one_work+0x54c/0×930 kernel/workqueue.c:2272
    worker_thread+0x82/0×830 kernel/workqueue.c:2418
    kthread+0x1ca/0×220 kernel/kthread.c:292
    ret_from_fork+0x1f/0×30 arch/x86/entry/entry_64.S:296

   Allocated by task 359:
     kasan_save_stack+0x1b/0×40 mm/kasan/common.c:48
     kasan_set_track mm/kasan/common.c:56 [inline]
     __kasan_kmalloc mm/kasan/common.c:461 [inline]
     __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:434
     kmalloc include/linux/slab.h:552 [inline]
     kzalloc include/linux/slab.h:664 [inline]
     ucma_process_join+0x16e/0×3f0 drivers/infiniband/core/ucma.c:1453
     ucma_join_multicast+0xda/0×140 drivers/infiniband/core/ucma.c:1538
     ucma_write+0x1f7/0×280 drivers/infiniband/core/ucma.c:1724
     vfs_write fs/read_write.c:603 [inline]
     vfs_write+0x191/0×4c0 fs/read_write.c:585
     ksys_write+0x1a1/0×1e0 fs/read_write.c:658
     do_syscall_64+0x2d/0×40 arch/x86/entry/common.c:46
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

   Freed by task 359:
     kasan_save_stack+0x1b/0×40 mm/kasan/common.c:48
     kasan_set_track+0x1c/0×30 mm/kasan/common.c:56
     kasan_set_free_info+0x1b/0×30 mm/kasan/generic.c:355
     __kasan_slab_free+0x112/0×160 mm/kasan/common.c:422
     slab_free_hook mm/slub.c:1544 [inline]
     slab_free_freelist_hook mm/slub.c:1577 [inline]
     slab_free mm/slub.c:3142 [inline]
     kfree+0xb3/0×3e0 mm/slub.c:4124
     ucma_process_join+0x22d/0×3f0 drivers/infiniband/core/ucma.c:1497
     ucma_join_multicast+0xda/0×140 drivers/infiniband/core/ucma.c:1538
     ucma_write+0x1f7/0×280 drivers/infiniband/core/ucma.c:1724
     vfs_write fs/read_write.c:603 [inline]
     vfs_write+0x191/0×4c0 fs/read_write.c:585
     ksys_write+0x1a1/0×1e0 fs/read_write.c:658
     do_syscall_64+0x2d/0×40 arch/x86/entry/common.c:46
     entry_SYSCALL_64_after_hwframe+0x44/0xa9
     The buggy address belongs to the object at ffff88810b3ad100
     which belongs to the cache kmalloc-192 of size 192
     The buggy address is located 16 bytes inside of
     192-byte region [ffff88810b3ad100, ffff88810b3ad1c0)

Fixes: b5de0c60cc ("RDMA/cma: Fix use after free race in roce multicast join")
Link: https://lore.kernel.org/r/20210211090517.1278415-1-leon@kernel.org
Reported-by: Amit Matityahu <mitm@nvidia.com>
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2021-02-16 14:42:59 -04:00
arch powerpc fixes for 5.11 #4 2021-01-17 12:28:58 -08:00
block block-5.11-2021-01-10 2021-01-10 12:53:08 -08:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto Char/Misc driver fixes for 5.11-rc3 2021-01-10 12:24:33 -08:00
Documentation ACPI fixes for 5.11-rc4 2021-01-15 10:55:33 -08:00
drivers RDMA/ucma: Fix use-after-free bug in ucma_create_uevent 2021-02-16 14:42:59 -04:00
fs Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-01-17 12:16:47 -08:00
include RDMA/ipoib: Remove racy Subnet Manager sendonly join checks 2021-02-16 14:42:58 -04:00
init Revert "init/console: Use ttynull as a fallback when there is no console" 2021-01-08 11:02:18 -08:00
ipc Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
kernel Blacklist properly on all archs 2021-01-11 14:37:13 -08:00
lib Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-01-17 12:16:47 -08:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
mm mm: don't put pinned pages into the swap cache 2021-01-17 12:08:04 -08:00
net Networking fixes for 5.11-rc4, including fixes from can and netfilter. 2021-01-14 13:31:07 -08:00
samples ARM: SoC drivers for v5.11 2020-12-16 16:38:41 -08:00
scripts Kbuild fixes for v5.11 2021-01-10 13:24:55 -08:00
security dump_common_audit_data(): fix racy accesses to ->d_name 2021-01-16 15:11:35 -05:00
sound ALSA: hda/hdmi - enable runtime pm for CI AMD display audio 2021-01-12 16:06:01 +01:00
tools tools/testing/scatterlist: Fix overflow of max segment size 2021-01-28 15:17:39 -04:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt x86: 2021-01-08 15:06:02 -08:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap RDMA 5.11 pull request 2020-12-16 13:42:26 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: dccp: move Gerrit Renker to CREDITS 2021-01-14 10:53:49 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2021-01-15 15:25:45 -08:00
Makefile Linux 5.11-rc4 2021-01-17 16:37:05 -08:00
README

Linux kernel
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Please read the Documentation/process/changes.rst file, as it contains the
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