| Message ID | 20211118070118.63756-1-starmiku1207184332@gmail.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Headers | show |
| Series | [v2] net: ethernet: dec: tulip: de4x5: fix possible array overflows in type3_infoblock() | expand |
On Thu, Nov 18, 2021 at 8:01 AM Teng Qi <starmiku1207184332@gmail.com> wrote: > > The definition of macro MOTO_SROM_BUG is: > #define MOTO_SROM_BUG (lp->active == 8 && (get_unaligned_le32( > dev->dev_addr) & 0x00ffffff) == 0x3e0008) > > and the if statement > if (MOTO_SROM_BUG) lp->active = 0; > > using this macro indicates lp->active could be 8. If lp->active is 8 and > the second comparison of this macro is false. lp->active will remain 8 in: > lp->phy[lp->active].gep = (*p ? p : NULL); p += (2 * (*p) + 1); > lp->phy[lp->active].rst = (*p ? p : NULL); p += (2 * (*p) + 1); > lp->phy[lp->active].mc = get_unaligned_le16(p); p += 2; > lp->phy[lp->active].ana = get_unaligned_le16(p); p += 2; > lp->phy[lp->active].fdx = get_unaligned_le16(p); p += 2; > lp->phy[lp->active].ttm = get_unaligned_le16(p); p += 2; > lp->phy[lp->active].mci = *p; > > However, the length of array lp->phy is 8, so array overflows can occur. > To fix these possible array overflows, we first check lp->active and then > return -EINVAL if it is greater or equal to ARRAY_SIZE(lp->phy) (i.e. 8). > > Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> > Signed-off-by: Teng Qi <starmiku1207184332@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Hello: This patch was applied to netdev/net.git (master) by David S. Miller <davem@davemloft.net>: On Thu, 18 Nov 2021 15:01:18 +0800 you wrote: > The definition of macro MOTO_SROM_BUG is: > #define MOTO_SROM_BUG (lp->active == 8 && (get_unaligned_le32( > dev->dev_addr) & 0x00ffffff) == 0x3e0008) > > and the if statement > if (MOTO_SROM_BUG) lp->active = 0; > > [...] Here is the summary with links: - [v2] net: ethernet: dec: tulip: de4x5: fix possible array overflows in type3_infoblock() https://git.kernel.org/netdev/net/c/0fa68da72c3b You are awesome, thank you!
diff --git a/drivers/net/ethernet/dec/tulip/de4x5.c b/drivers/net/ethernet/dec/tulip/de4x5.c index 13121c4dcfe6..828b9642fd68 100644 --- a/drivers/net/ethernet/dec/tulip/de4x5.c +++ b/drivers/net/ethernet/dec/tulip/de4x5.c @@ -4709,6 +4709,10 @@ type3_infoblock(struct net_device *dev, u_char count, u_char *p) lp->ibn = 3; lp->active = *p++; if (MOTO_SROM_BUG) lp->active = 0; + /* if (MOTO_SROM_BUG) statement indicates lp->active could + * be 8 (i.e. the size of array lp->phy) */ + if (WARN_ON(lp->active >= ARRAY_SIZE(lp->phy))) + return -EINVAL; lp->phy[lp->active].gep = (*p ? p : NULL); p += (2 * (*p) + 1); lp->phy[lp->active].rst = (*p ? p : NULL); p += (2 * (*p) + 1); lp->phy[lp->active].mc = get_unaligned_le16(p); p += 2;
The definition of macro MOTO_SROM_BUG is: #define MOTO_SROM_BUG (lp->active == 8 && (get_unaligned_le32( dev->dev_addr) & 0x00ffffff) == 0x3e0008) and the if statement if (MOTO_SROM_BUG) lp->active = 0; using this macro indicates lp->active could be 8. If lp->active is 8 and the second comparison of this macro is false. lp->active will remain 8 in: lp->phy[lp->active].gep = (*p ? p : NULL); p += (2 * (*p) + 1); lp->phy[lp->active].rst = (*p ? p : NULL); p += (2 * (*p) + 1); lp->phy[lp->active].mc = get_unaligned_le16(p); p += 2; lp->phy[lp->active].ana = get_unaligned_le16(p); p += 2; lp->phy[lp->active].fdx = get_unaligned_le16(p); p += 2; lp->phy[lp->active].ttm = get_unaligned_le16(p); p += 2; lp->phy[lp->active].mci = *p; However, the length of array lp->phy is 8, so array overflows can occur. To fix these possible array overflows, we first check lp->active and then return -EINVAL if it is greater or equal to ARRAY_SIZE(lp->phy) (i.e. 8). Reported-by: TOTE Robot <oslab@tsinghua.edu.cn> Signed-off-by: Teng Qi <starmiku1207184332@gmail.com> --- v2: * Check lp->active in separate if statement within macro WARN_ON() and return -EINVAL if it is greater or equal to ARRAY_SIZE(lp->phy). Instead of checking lp->active and MOTO_SROM_BUG together in the same if statement. Thank Arnd Bergmann for helpful and friendly suggestion. --- drivers/net/ethernet/dec/tulip/de4x5.c | 4 ++++ 1 file changed, 4 insertions(+)