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| author | Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> | 2006-08-17 16:44:46 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2006-08-17 16:44:46 -0700 |
| commit | 6e8fcbf64024f9056ba122abbb66554aa76bae5d (patch) | |
| tree | 61fec2bd4815d30110dc2ba7da3b7578fb08a0d8 /net | |
| parent | acd6e00b8e4db542cb6bc9ddfbb4e18bbe29ce4d (diff) | |
| download | linux-6e8fcbf64024f9056ba122abbb66554aa76bae5d.tar.gz linux-6e8fcbf64024f9056ba122abbb66554aa76bae5d.tar.bz2 linux-6e8fcbf64024f9056ba122abbb66554aa76bae5d.zip | |
[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: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -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 9be53a8e72c3..51738000f3dc 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -159,7 +159,7 @@ 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) @@ -172,7 +172,7 @@ 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) @@ -598,7 +598,7 @@ 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; @@ -639,7 +639,7 @@ 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); @@ -820,7 +820,7 @@ 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) { @@ -839,7 +839,7 @@ 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: |