Messages in this thread | | | Date | Fri, 23 Apr 2004 09:14:32 +0200 | From | Peter Waechtler <> | Subject | Re: [PATCH] coredump - as root not only if euid switched |
| |
On Thursday, April 22, 2004, at 10:05PM, Linus Torvalds <torvalds@osdl.org> wrote:
> > >On Thu, 22 Apr 2004, Peter W�chtler wrote: >> >> > hm, OK. There's a window in which someone can come in and recreate the >> > file, but the open is using O_EXCL|O_CREATE so that seems safe enough. >> >> So here is the updated patch with an open coded call to sys_unlink > >Aughr. > >Wouldn't it be much nicer to just refuse to overwrite files owned by >anybody else? > >In other words, I'd much rather see a patch that is a much simpler one, >which just says: if we opened an existing file, we won't touch it if we >weren't the owners of it. > >That should be safe for root _and_ it should be safe for people who >already had a file descriptor open previously (hey, if the previous >root-owned core-file was world readable, then what else is new?) >
the previous core was owned by user.donttellyourwisdom The root process happily dumps it's core into it, doesn't change ownership nor permissions.
>Tell me why this isn't simpler? > I can't it's simpler. If you are interested in the core (you don't because you don't make errors, you don't even use debuggers but change the VM ;> ) you get it, otherwise you have an old one.
> >--- >--- 1.111/fs/exec.c Wed Apr 21 02:11:57 2004 >+++ edited/fs/exec.c Thu Apr 22 13:03:27 2004 >@@ -1378,6 +1378,8 @@ > inode = file->f_dentry->d_inode; > if (inode->i_nlink > 1) > goto close_fail; /* multiple links - don't dump */ >+ if (inode->i_uid != current->euid || inode->i_gid != current->egid) >+ goto close_fail; > if (d_unhashed(file->f_dentry)) > goto close_fail; > > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |