Messages in this thread |  | | Date | Thu, 6 Sep 2001 15:10:34 -0400 (EDT) | From | Alexander Viro <> | Subject | Re: OOPS: reproducible in vfs_follow_link 2.4.9,2.4.10-pre4 |
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On Thu, 6 Sep 2001, Giacomo Catenazzi wrote:
> Hello. > > Since yesterdey, every time I run a 2.4.9 or 2.4.10pre-4 without the > "devfs=nomount" I > have two oops + /usr, /home /boot not mounted (all (also /): ext2).
Don't use devfs. One of the known bugs - devfs passes a string to vfs_follow_link() and doesn't care to preserve it until vfs_follow_link() is done.
E.g. rmmod during the symlink traversal will end up with
vfs_follow_link(nd, s) [working] [blocked on IO/allocation/whatever] rmmod ... kfree(s) ... [the first process wakes up and oopses on attempt to dereference s]
There are other scenarios that end up freeing a string passed to vfs_follow_link() (or, for that matter, being busily copied to userland by readlink(2)). Basically, if devfs decides that symlink is gone - pray. If it's being accessed right now you are going to end up with oops.
No idea why you've started triggering it only now - not enough details to say.
And yes, Richard had been informed about that months ago. Sigh...
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