Kuniyuki Iwashima a9c65c7efb UPSTREAM: netfilter: ipset: Add schedule point in call_ad().
[ Upstream commit 24e227896b ]

syzkaller found a repro that causes Hung Task [0] with ipset.  The repro
first creates an ipset and then tries to delete a large number of IPs
from the ipset concurrently:

  IPSET_ATTR_IPADDR_IPV4 : 172.20.20.187
  IPSET_ATTR_CIDR        : 2

The first deleting thread hogs a CPU with nfnl_lock(NFNL_SUBSYS_IPSET)
held, and other threads wait for it to be released.

Previously, the same issue existed in set->variant->uadt() that could run
so long under ip_set_lock(set).  Commit 5e29dc36bd ("netfilter: ipset:
Rework long task execution when adding/deleting entries") tried to fix it,
but the issue still exists in the caller with another mutex.

While adding/deleting many IPs, we should release the CPU periodically to
prevent someone from abusing ipset to hang the system.

Note we need to increment the ipset's refcnt to prevent the ipset from
being destroyed while rescheduling.

[0]:
INFO: task syz-executor174:268 blocked for more than 143 seconds.
      Not tainted 6.4.0-rc1-00145-gba79e9a73284 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor174 state:D stack:0     pid:268   ppid:260    flags:0x0000000d
Call trace:
 __switch_to+0x308/0x714 arch/arm64/kernel/process.c:556
 context_switch kernel/sched/core.c:5343 [inline]
 __schedule+0xd84/0x1648 kernel/sched/core.c:6669
 schedule+0xf0/0x214 kernel/sched/core.c:6745
 schedule_preempt_disabled+0x58/0xf0 kernel/sched/core.c:6804
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6fc/0xdb0 kernel/locking/mutex.c:747
 __mutex_lock_slowpath+0x14/0x20 kernel/locking/mutex.c:1035
 mutex_lock+0x98/0xf0 kernel/locking/mutex.c:286
 nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
 nfnetlink_rcv_msg+0x480/0x70c net/netfilter/nfnetlink.c:295
 netlink_rcv_skb+0x1c0/0x350 net/netlink/af_netlink.c:2546
 nfnetlink_rcv+0x18c/0x199c net/netfilter/nfnetlink.c:658
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x664/0x8cc net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x6d0/0xa4c net/netlink/af_netlink.c:1913
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x4b8/0x810 net/socket.c:2503
 ___sys_sendmsg net/socket.c:2557 [inline]
 __sys_sendmsg+0x1f8/0x2a4 net/socket.c:2586
 __do_sys_sendmsg net/socket.c:2595 [inline]
 __se_sys_sendmsg net/socket.c:2593 [inline]
 __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2593
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x84/0x270 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x134/0x24c arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193
 el0_svc+0x2c/0x7c arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591

Bug: 303172721
Reported-by: syzkaller <syzkaller@googlegroups.com>
Fixes: a7b4f989a6 ("netfilter: ipset: IP set core support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit fea199dbf6)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I7d2c299b1d7d298b5abd76306821320546338a77
2023-10-24 15:14:15 +01:00
2023-02-09 13:29:55 +00:00
2022-09-28 09:02:20 +02:00
2022-09-28 09:02:20 +02:00
2023-06-15 09:54:33 +01:00
2022-08-22 16:34:52 +00:00

How do I submit patches to Android Common Kernels

  1. BEST: Make all of your changes to upstream Linux. If appropriate, backport to the stable releases. These patches will be merged automatically in the corresponding common kernels. If the patch is already in upstream Linux, post a backport of the patch that conforms to the patch requirements below.

    • Do not send patches upstream that contain only symbol exports. To be considered for upstream Linux, additions of EXPORT_SYMBOL_GPL() require an in-tree modular driver that uses the symbol -- so include the new driver or changes to an existing driver in the same patchset as the export.
    • When sending patches upstream, the commit message must contain a clear case for why the patch is needed and beneficial to the community. Enabling out-of-tree drivers or functionality is not not a persuasive case.
  2. LESS GOOD: Develop your patches out-of-tree (from an upstream Linux point-of-view). Unless these are fixing an Android-specific bug, these are very unlikely to be accepted unless they have been coordinated with kernel-team@android.com. If you want to proceed, post a patch that conforms to the patch requirements below.

Common Kernel patch requirements

  • All patches must conform to the Linux kernel coding standards and pass scripts/checkpatch.pl
  • Patches shall not break gki_defconfig or allmodconfig builds for arm, arm64, x86, x86_64 architectures (see https://source.android.com/setup/build/building-kernels)
  • If the patch is not merged from an upstream branch, the subject must be tagged with the type of patch: UPSTREAM:, BACKPORT:, FROMGIT:, FROMLIST:, or ANDROID:.
  • All patches must have a Change-Id: tag (see https://gerrit-review.googlesource.com/Documentation/user-changeid.html)
  • If an Android bug has been assigned, there must be a Bug: tag.
  • All patches must have a Signed-off-by: tag by the author and the submitter

Additional requirements are listed below based on patch type

Requirements for backports from mainline Linux: UPSTREAM:, BACKPORT:

  • If the patch is a cherry-pick from Linux mainline with no changes at all
    • tag the patch subject with UPSTREAM:.
    • add upstream commit information with a (cherry picked from commit ...) line
    • Example:
      • if the upstream commit message is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>
  • then Joe Smith would upload the patch for the common kernel as
        UPSTREAM: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch requires any changes from the upstream version, tag the patch with BACKPORT: instead of UPSTREAM:.
    • use the same tags as UPSTREAM:
    • add comments about the changes under the (cherry picked from commit ...) line
    • Example:
        BACKPORT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        [joe: Resolved minor conflict in drivers/foo/bar.c ]
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for other backports: FROMGIT:, FROMLIST:,

  • If the patch has been merged into an upstream maintainer tree, but has not yet been merged into Linux mainline
    • tag the patch subject with FROMGIT:
    • add info on where the patch came from as (cherry picked from commit <sha1> <repo> <branch>). This must be a stable maintainer branch (not rebased, so don't use linux-next for example).
    • if changes were required, use BACKPORT: FROMGIT:
    • Example:
      • if the commit message in the maintainer tree is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>
  • then Joe Smith would upload the patch for the common kernel as
        FROMGIT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        (cherry picked from commit 878a2fd9de10b03d11d2f622250285c7e63deace
         https://git.kernel.org/pub/scm/linux/kernel/git/foo/bar.git test-branch)
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch has been submitted to LKML, but not accepted into any maintainer tree
    • tag the patch subject with FROMLIST:
    • add a Link: tag with a link to the submittal on lore.kernel.org
    • add a Bug: tag with the Android bug (required for patches not accepted into a maintainer tree)
    • if changes were required, use BACKPORT: FROMLIST:
    • Example:
        FROMLIST: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Link: https://lore.kernel.org/lkml/20190619171517.GA17557@someone.com/
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for Android-specific patches: ANDROID:

  • If the patch is fixing a bug to Android-specific code
    • tag the patch subject with ANDROID:
    • add a Fixes: tag that cites the patch with the bug
    • Example:
        ANDROID: fix android-specific bug in foobar.c

        This is the detailed description of the important fix

        Fixes: 1234abcd2468 ("foobar: add cool feature")
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch is a new feature
    • tag the patch subject with ANDROID:
    • add a Bug: tag with the Android bug (required for android-specific features)
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