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  15. Jul 10, 2020
    • Jens Axboe's avatar
      io_uring: account user memory freed when exit has been queued · 309fc03a
      Jens Axboe authored 
      

We currently account the memory after the exit work has been run, but
that leaves a gap where a process has closed its ring and until the
memory has been accounted as freed. If the memlocked ulimit is
borderline, then that can introduce spurious setup errors returning
-ENOMEM because the free work hasn't been run yet.

Account this as freed when we close the ring, as not to expose a tiny
gap where setting up a new ring can fail.

Fixes: 85faa7b8 ("io_uring: punt final io_ring_ctx wait-and-free to workqueue")
Cc: stable@vger.kernel.org # v5.7
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      309fc03a
    • Yang Yingliang's avatar
      io_uring: fix memleak in io_sqe_files_register() · 667e57da
      Yang Yingliang authored 
      

I got a memleak report when doing some fuzz test:

BUG: memory leak
unreferenced object 0x607eeac06e78 (size 8):
  comm "test", pid 295, jiffies 4294735835 (age 31.745s)
  hex dump (first 8 bytes):
    00 00 00 00 00 00 00 00                          ........
  backtrace:
    [<00000000932632e6>] percpu_ref_init+0x2a/0x1b0
    [<0000000092ddb796>] __io_uring_register+0x111d/0x22a0
    [<00000000eadd6c77>] __x64_sys_io_uring_register+0x17b/0x480
    [<00000000591b89a6>] do_syscall_64+0x56/0xa0
    [<00000000864a281d>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Call percpu_ref_exit() on error path to avoid
refcount memleak.

Fixes: 05f3fb3c ("io_uring: avoid ring quiesce for fixed file set unregister and update")
Cc: stable@vger.kernel.org
Reported-by: default avatarHulk Robot <hulkci@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      667e57da
  17. Jul 09, 2020
    • Christoph Hellwig's avatar
      btrfs: wire up iter_file_splice_write · d7776591
      Christoph Hellwig authored 
      

btrfs implements the iter_write op and thus can use the more efficient
iov_iter based splice implementation.  For now falling back to the less
efficient default is pretty harmless, but I have a pending series that
removes the default, and thus would cause btrfs to not support splice
at all.

Reported-by: default avatarAndy Lavr <andy.lavr@gmail.com>
Tested-by: default avatarAndy Lavr <andy.lavr@gmail.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
      d7776591
    • Josef Bacik's avatar
      btrfs: fix double put of block group with nocow · 230ed397
      Josef Bacik authored 
      

While debugging a patch that I wrote I was hitting use-after-free panics
when accessing block groups on unmount.  This turned out to be because
in the nocow case if we bail out of doing the nocow for whatever reason
we need to call btrfs_dec_nocow_writers() if we called the inc.  This
puts our block group, but a few error cases does

if (nocow) {
    btrfs_dec_nocow_writers();
    goto error;
}

unfortunately, error is

error:
	if (nocow)
		btrfs_dec_nocow_writers();

so we get a double put on our block group.  Fix this by dropping the
error cases calling of btrfs_dec_nocow_writers(), as it's handled at the
error label now.

Fixes: 762bf098 ("btrfs: improve error handling in run_delalloc_nocow")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
      230ed397
    • Steve French's avatar
      cifs: update internal module version number · a8dab63e
      Steve French authored 
      

        To 2.28

Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      a8dab63e
    • Ronnie Sahlberg's avatar
      cifs: fix reference leak for tlink · a77592a7
      Ronnie Sahlberg authored 
      

Don't leak a reference to tlink during the NOTIFY ioctl

Signed-off-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
Reviewed-by: default avatarAurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org> # v5.6+
      a77592a7
    • Yang Yingliang's avatar
      io_uring: fix memleak in __io_sqe_files_update() · f3bd9dae
      Yang Yingliang authored 
      

I got a memleak report when doing some fuzz test:

BUG: memory leak
unreferenced object 0xffff888113e02300 (size 488):
comm "syz-executor401", pid 356, jiffies 4294809529 (age 11.954s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
a0 a4 ce 19 81 88 ff ff 60 ce 09 0d 81 88 ff ff ........`.......
backtrace:
[<00000000129a84ec>] kmem_cache_zalloc include/linux/slab.h:659 [inline]
[<00000000129a84ec>] __alloc_file+0x25/0x310 fs/file_table.c:101
[<000000003050ad84>] alloc_empty_file+0x4f/0x120 fs/file_table.c:151
[<000000004d0a41a3>] alloc_file+0x5e/0x550 fs/file_table.c:193
[<000000002cb242f0>] alloc_file_pseudo+0x16a/0x240 fs/file_table.c:233
[<00000000046a4baa>] anon_inode_getfile fs/anon_inodes.c:91 [inline]
[<00000000046a4baa>] anon_inode_getfile+0xac/0x1c0 fs/anon_inodes.c:74
[<0000000035beb745>] __do_sys_perf_event_open+0xd4a/0x2680 kernel/events/core.c:11720
[<0000000049009dc7>] do_syscall_64+0x56/0xa0 arch/x86/entry/common.c:359
[<00000000353731ca>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff8881152dd5e0 (size 16):
comm "syz-executor401", pid 356, jiffies 4294809529 (age 11.954s)
hex dump (first 16 bytes):
01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000074caa794>] kmem_cache_zalloc include/linux/slab.h:659 [inline]
[<0000000074caa794>] lsm_file_alloc security/security.c:567 [inline]
[<0000000074caa794>] security_file_alloc+0x32/0x160 security/security.c:1440
[<00000000c6745ea3>] __alloc_file+0xba/0x310 fs/file_table.c:106
[<000000003050ad84>] alloc_empty_file+0x4f/0x120 fs/file_table.c:151
[<000000004d0a41a3>] alloc_file+0x5e/0x550 fs/file_table.c:193
[<000000002cb242f0>] alloc_file_pseudo+0x16a/0x240 fs/file_table.c:233
[<00000000046a4baa>] anon_inode_getfile fs/anon_inodes.c:91 [inline]
[<00000000046a4baa>] anon_inode_getfile+0xac/0x1c0 fs/anon_inodes.c:74
[<0000000035beb745>] __do_sys_perf_event_open+0xd4a/0x2680 kernel/events/core.c:11720
[<0000000049009dc7>] do_syscall_64+0x56/0xa0 arch/x86/entry/common.c:359
[<00000000353731ca>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

If io_sqe_file_register() failed, we need put the file that get by fget()
to avoid the memleak.

Fixes: c3a31e60 ("io_uring: add support for IORING_REGISTER_FILES_UPDATE")
Cc: stable@vger.kernel.org
Reported-by: default avatarHulk Robot <hulkci@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      f3bd9dae
    • Xiaoguang Wang's avatar
      io_uring: export cq overflow status to userspace · 6d5f9049
      Xiaoguang Wang authored 
      

For those applications which are not willing to use io_uring_enter()
to reap and handle cqes, they may completely rely on liburing's
io_uring_peek_cqe(), but if cq ring has overflowed, currently because
io_uring_peek_cqe() is not aware of this overflow, it won't enter
kernel to flush cqes, below test program can reveal this bug:

static void test_cq_overflow(struct io_uring *ring)
{
        struct io_uring_cqe *cqe;
        struct io_uring_sqe *sqe;
        int issued = 0;
        int ret = 0;

        do {
                sqe = io_uring_get_sqe(ring);
                if (!sqe) {
                        fprintf(stderr, "get sqe failed\n");
                        break;;
                }
                ret = io_uring_submit(ring);
                if (ret <= 0) {
                        if (ret != -EBUSY)
                                fprintf(stderr, "sqe submit failed: %d\n", ret);
                        break;
                }
                issued++;
        } while (ret > 0);
        assert(ret == -EBUSY);

        printf("issued requests: %d\n", issued);

        while (issued) {
                ret = io_uring_peek_cqe(ring, &cqe);
                if (ret) {
                        if (ret != -EAGAIN) {
                                fprintf(stderr, "peek completion failed: %s\n",
                                        strerror(ret));
                                break;
                        }
                        printf("left requets: %d\n", issued);
                        continue;
                }
                io_uring_cqe_seen(ring, cqe);
                issued--;
                printf("left requets: %d\n", issued);
        }
}

int main(int argc, char *argv[])
{
        int ret;
        struct io_uring ring;

        ret = io_uring_queue_init(16, &ring, 0);
        if (ret) {
                fprintf(stderr, "ring setup failed: %d\n", ret);
                return 1;
        }

        test_cq_overflow(&ring);
        return 0;
}

To fix this issue, export cq overflow status to userspace by adding new
IORING_SQ_CQ_OVERFLOW flag, then helper functions() in liburing, such as
io_uring_peek_cqe, can be aware of this cq overflow and do flush accordingly.

Signed-off-by: default avatarXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      6d5f9049
  19. Jul 08, 2020