From: Vegard Nossum <vegard.nossum@oracle.com>
To: Luis Chamberlain <mcgrof@kernel.org>
Cc: George Kennedy <george.kennedy@oracle.com>,
linux-kernel@vger.kernel.org, linux-modules@vger.kernel.org,
Vegard Nossum <vegard.nossum@oracle.com>,
Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>,
syzbot+9c2bdc9d24e4a7abe741@syzkaller.appspotmail.com,
Johan Hovold <johan@kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
Rudi Heitbaum <rudi@heitbaum.com>,
David Hildenbrand <david@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH] module: always complete idempotent loads
Date: Tue, 4 Jul 2023 12:08:52 +0200 [thread overview]
Message-ID: <20230704100852.23452-1-vegard.nossum@oracle.com> (raw)
In-Reply-To: <20230704092309.22669-1-vegard.nossum@oracle.com>
Commit 9b9879fc0327 added a hashtable storing lists of concurrent module
loads. However, it didn't fix up all the error paths in
init_module_from_file(); this would lead to leaving the function while an
on-stack 'struct idempotent' element is still in the hash table, which
leads to all sorts of badness as spotted by syzkaller:
BUG: soft lockup in sys_finit_module
BUG: unable to handle kernel paging request in init_module_from_file
general protection fault in init_module_from_file
INFO: task hung in init_module_from_file
KASAN: out-of-bounds Read in init_module_from_file
KASAN: slab-out-of-bounds Read in init_module_from_file
KASAN: slab-use-after-free Read in init_module_from_file
KASAN: slab-use-after-free Read in set_powered_sync
KASAN: stack-out-of-bounds Read in init_module_from_file
KASAN: use-after-free in init_module_from_file
KASAN: use-after-free Read in init_module_from_file
Fixes: 9b9879fc0327 ("modules: catch concurrent module loads, treat them as idempotent")
Reported-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reported-by: syzbot+9c2bdc9d24e4a7abe741@syzkaller.appspotmail.com
Tested-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Johan Hovold <johan@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Rudi Heitbaum <rudi@heitbaum.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
---
kernel/module/main.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/kernel/module/main.c b/kernel/module/main.c
index d6de66a6a1ac..6100d0373f2f 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3121,39 +3121,42 @@ static void idempotent_complete(struct idempotent *u, int ret)
static int init_module_from_file(struct file *f, const char __user * uargs, int flags)
{
struct idempotent idem;
struct load_info info = { };
void *buf = NULL;
int len, ret;
if (!f || !(f->f_mode & FMODE_READ))
return -EBADF;
if (idempotent(&idem, file_inode(f))) {
wait_for_completion(&idem.complete);
return idem.ret;
}
len = kernel_read_file(f, 0, &buf, INT_MAX, NULL, READING_MODULE);
if (len < 0) {
mod_stat_inc(&failed_kreads);
mod_stat_add_long(len, &invalid_kread_bytes);
- return len;
+ ret = len;
+ goto out;
}
if (flags & MODULE_INIT_COMPRESSED_FILE) {
int err = module_decompress(&info, buf, len);
vfree(buf); /* compressed data is no longer needed */
if (err) {
mod_stat_inc(&failed_decompress);
mod_stat_add_long(len, &invalid_decompress_bytes);
- return err;
+ ret = err;
+ goto out;
}
} else {
info.hdr = buf;
info.len = len;
}
ret = load_module(&info, uargs, flags);
+out:
idempotent_complete(&idem, ret);
return ret;
}
--
next parent reply other threads:[~2023-07-04 10:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20230704092309.22669-1-vegard.nossum@oracle.com>
2023-07-04 10:08 ` Vegard Nossum [this message]
2023-07-04 13:37 ` [PATCH] module: always complete idempotent loads Linus Torvalds
2023-07-04 15:11 ` Vegard Nossum
2023-07-04 17:10 ` Linus Torvalds
2023-07-04 18:28 ` Vegard Nossum
2023-07-04 18:38 ` Linus Torvalds
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