-stable review patch. If anyone has any objections, please let us know.
------------------
From: Alexey Kuznetsov <[email protected]>
[IPV4]: severe locking bug in fib_semantics.c
Found in 2.4 by Yixin Pan <[email protected]>.
> When I read fib_semantics.c of Linux-2.4.32, write_lock(&fib_info_lock) =
> is used in fib_release_info() instead of write_lock_bh(&fib_info_lock). =
> Is the following case possible: a BH interrupts fib_release_info() while =
> holding the write lock, and calls ip_check_fib_default() which calls =
> read_lock(&fib_info_lock), and spin forever.
Signed-off-by: Alexey Kuznetsov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/ipv4/fib_semantics.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- linux-2.6.17.9.orig/net/ipv4/fib_semantics.c
+++ linux-2.6.17.9/net/ipv4/fib_semantics.c
@@ -160,7 +160,7 @@ void free_fib_info(struct fib_info *fi)
void fib_release_info(struct fib_info *fi)
{
- write_lock(&fib_info_lock);
+ write_lock_bh(&fib_info_lock);
if (fi && --fi->fib_treeref == 0) {
hlist_del(&fi->fib_hash);
if (fi->fib_prefsrc)
@@ -173,7 +173,7 @@ void fib_release_info(struct fib_info *f
fi->fib_dead = 1;
fib_info_put(fi);
}
- write_unlock(&fib_info_lock);
+ write_unlock_bh(&fib_info_lock);
}
static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
@@ -599,7 +599,7 @@ static void fib_hash_move(struct hlist_h
unsigned int old_size = fib_hash_size;
unsigned int i, bytes;
- write_lock(&fib_info_lock);
+ write_lock_bh(&fib_info_lock);
old_info_hash = fib_info_hash;
old_laddrhash = fib_info_laddrhash;
fib_hash_size = new_size;
@@ -640,7 +640,7 @@ static void fib_hash_move(struct hlist_h
}
fib_info_laddrhash = new_laddrhash;
- write_unlock(&fib_info_lock);
+ write_unlock_bh(&fib_info_lock);
bytes = old_size * sizeof(struct hlist_head *);
fib_hash_free(old_info_hash, bytes);
@@ -822,7 +822,7 @@ link_it:
fi->fib_treeref++;
atomic_inc(&fi->fib_clntref);
- write_lock(&fib_info_lock);
+ write_lock_bh(&fib_info_lock);
hlist_add_head(&fi->fib_hash,
&fib_info_hash[fib_info_hashfn(fi)]);
if (fi->fib_prefsrc) {
@@ -841,7 +841,7 @@ link_it:
head = &fib_info_devhash[hash];
hlist_add_head(&nh->nh_hash, head);
} endfor_nexthops(fi)
- write_unlock(&fib_info_lock);
+ write_unlock_bh(&fib_info_lock);
return fi;
err_inval:
--
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
