diff options
| author | Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> | 2006-12-14 22:28:51 +0100 |
|---|---|---|
| committer | Adrian Bunk <bunk@stusta.de> | 2006-12-14 22:28:51 +0100 |
| commit | 2a9d7dbf7566a36221b4066e57f4c3212bff1ef0 (patch) | |
| tree | 5d77b44e9394bd0e10b66681792af18d52540636 | |
| parent | 594834bc754f243ddc3d16b9cac354702101c719 (diff) | |
[IPV4]: severe locking bug in fib_semantics.c
Found in 2.4 by Yixin Pan <yxpan@hotmail.com>.
> 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 <kuznet@ms2.inr.ac.ru>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
| -rw-r--r-- | net/ipv4/fib_semantics.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 0f4145babb14..1de08c18637b 100644 --- a/net/ipv4/fib_semantics.c +++ b/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 *fi) 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_head *new_info_hash, 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_head *new_info_hash, } 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: |