lkml.org 
[lkml]   [2011]   [Feb]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: OOPS in configfs when doing d_delete
    On Mon, Feb 21, 2011 at 11:20:18AM +0100, Jiri Slaby wrote:
    > when configfs_attach_group fails in configfs_register_subsystem:
    > dentry = d_alloc(configfs_sb->s_root, &name);
    > if (dentry) {
    > d_add(dentry, NULL);
    >
    > err = configfs_attach_group(sd->s_element, &group->cg_item,
    > dentry);
    > if (err) {
    > d_delete(dentry);
    > dput(dentry);
    >
    >
    > d_delete kills the kernel. I don't know what the actual bug is here, but
    > d_delete looks broken anyway:
    > spin_lock(&dentry->d_lock);
    > inode = dentry->d_inode;
    > isdir = S_ISDIR(inode->i_mode); <======== dereference
    > if (dentry->d_count == 1) {
    > if (inode && !spin_trylock(&inode->i_lock)) {
    > ^^^^^ <============= test
    >
    > It seems like a superfluous test, not a potential null dereference to
    > me, right?

    I think you're right about the superfluous test, but I need more
    investigation to see what's going on. Thanks for the report.
    What was causing attach_group() to fail? Do you know?

    Joel

    --

    Life's Little Instruction Book #444

    "Never underestimate the power of a kind word or deed."

    http://www.jlbec.org/
    jlbec@evilplan.org


    \
     
     \ /
      Last update: 2011-02-21 11:47    [W:0.025 / U:61.912 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site