Messages in this thread Patch in this message | | | Date | Thu, 22 Apr 2004 13:05:51 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH] coredump - as root not only if euid switched |
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On Thu, 22 Apr 2004, Peter Wächtler 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?)
Tell me why this isn't simpler?
Linus
--- --- 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/
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