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| author | David S. Miller <davem@davemloft.net> | 2011-02-14 01:50:45 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-02-14 01:51:37 +0100 |
| commit | c978e7bb77dfd2cd3d1f547fa4e395cfe47f02b2 (patch) | |
| tree | b77cb1058d7821a9cdb8fcc7a8d6d3759f63743e /drivers/isdn | |
| parent | USB Network driver infrastructure: Fix leak when usb_autopm_get_interface() r... (diff) | |
| download | linux-c978e7bb77dfd2cd3d1f547fa4e395cfe47f02b2.tar.xz linux-c978e7bb77dfd2cd3d1f547fa4e395cfe47f02b2.zip | |
hisax: Fix unchecked alloc_skb() return.
Jesper Juhl noticed that l2_pull_iqueue() does not
check to see if alloc_skb() fails.
Fix this by first trying to reallocate the headroom
if necessary, rather than later after we've made hard
to undo state changes.
Reported-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/isdn')
| -rw-r--r-- | drivers/isdn/hisax/isdnl2.c | 35 |
1 files changed, 20 insertions, 15 deletions
diff --git a/drivers/isdn/hisax/isdnl2.c b/drivers/isdn/hisax/isdnl2.c index 0858791978d8..98ac835281fe 100644 --- a/drivers/isdn/hisax/isdnl2.c +++ b/drivers/isdn/hisax/isdnl2.c @@ -1243,14 +1243,21 @@ l2_st7_tout_203(struct FsmInst *fi, int event, void *arg) st->l2.rc = 0; } +static int l2_hdr_space_needed(struct Layer2 *l2) +{ + int len = test_bit(FLG_LAPD, &l2->flag) ? 2 : 1; + + return len + (test_bit(FLG_LAPD, &l2->flag) ? 2 : 1); +} + static void l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) { struct PStack *st = fi->userdata; - struct sk_buff *skb, *oskb; + struct sk_buff *skb; struct Layer2 *l2 = &st->l2; u_char header[MAX_HEADER_LEN]; - int i; + int i, hdr_space_needed; int unsigned p1; u_long flags; @@ -1261,6 +1268,16 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) if (!skb) return; + hdr_space_needed = l2_hdr_space_needed(l2); + if (hdr_space_needed > skb_headroom(skb)) { + struct sk_buff *orig_skb = skb; + + skb = skb_realloc_headroom(skb, hdr_space_needed); + if (!skb) { + dev_kfree_skb(orig_skb); + return; + } + } spin_lock_irqsave(&l2->lock, flags); if(test_bit(FLG_MOD128, &l2->flag)) p1 = (l2->vs - l2->va) % 128; @@ -1285,19 +1302,7 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) l2->vs = (l2->vs + 1) % 8; } spin_unlock_irqrestore(&l2->lock, flags); - p1 = skb->data - skb->head; - if (p1 >= i) - memcpy(skb_push(skb, i), header, i); - else { - printk(KERN_WARNING - "isdl2 pull_iqueue skb header(%d/%d) too short\n", i, p1); - oskb = skb; - skb = alloc_skb(oskb->len + i, GFP_ATOMIC); - memcpy(skb_put(skb, i), header, i); - skb_copy_from_linear_data(oskb, - skb_put(skb, oskb->len), oskb->len); - dev_kfree_skb(oskb); - } + memcpy(skb_push(skb, i), header, i); st->l2.l2l1(st, PH_PULL | INDICATION, skb); test_and_clear_bit(FLG_ACK_PEND, &st->l2.flag); if (!test_and_set_bit(FLG_T200_RUN, &st->l2.flag)) { |