[PATCH openEuler-1.0-LTS 1/2] ovl: get_acl: Fix null pointer dereference at realinode in rcu-walk mode
From: Zhihao Cheng <chengzhihao1@huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I70MZX CVE: NA -------------------------------- Following process: P1 P2 path_openat link_path_walk may_lookup inode_permission(rcu) ovl_permission acl_permission_check check_acl get_cached_acl_rcu ovl_get_inode_acl realinode = ovl_inode_real(ovl_inode) drop_cache __dentry_kill(ovl_dentry) iput(ovl_inode) ovl_destroy_inode(ovl_inode) dput(oi->__upperdentry) dentry_kill(upperdentry) dentry_unlink_inode upperdentry->d_inode = NULL ovl_inode_upper upperdentry = ovl_i_dentry_upper(ovl_inode) d_inode(upperdentry) // returns NULL IS_POSIXACL(realinode) // NULL pointer dereference , will trigger an null pointer dereference at realinode: [ 205.472797] BUG: kernel NULL pointer dereference, address: 0000000000000028 [ 205.476701] CPU: 2 PID: 2713 Comm: ls Not tainted 6.3.0-12064-g2edfa098e750-dirty #1216 [ 205.478754] RIP: 0010:do_ovl_get_acl+0x5d/0x300 [ 205.489584] Call Trace: [ 205.489812] <TASK> [ 205.490014] ovl_get_inode_acl+0x26/0x30 [ 205.490466] get_cached_acl_rcu+0x61/0xa0 [ 205.490908] generic_permission+0x1bf/0x4e0 [ 205.491447] ovl_permission+0x79/0x1b0 [ 205.491917] inode_permission+0x15e/0x2c0 [ 205.492425] link_path_walk+0x115/0x550 [ 205.493311] path_lookupat.isra.0+0xb2/0x200 [ 205.493803] filename_lookup+0xda/0x240 [ 205.495747] vfs_fstatat+0x7b/0xb0 Fetch a reproducer in [Link]. Fix it by checking realinode whether to be NULL before accessing it. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217404 Fixes: 332f606b32b6 ("ovl: enable RCU'd ->get_acl()") Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- fs/overlayfs/inode.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 5c82c95e57d2..3a35623b86e1 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -428,7 +428,15 @@ struct posix_acl *ovl_get_acl(struct inode *inode, int type, bool rcu) const struct cred *old_cred; struct posix_acl *acl; - if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !IS_POSIXACL(realinode)) + if (!IS_ENABLED(CONFIG_FS_POSIX_ACL)) + return NULL; + + if (!realinode) { + WARN_ON(!rcu); + return ERR_PTR(-ECHILD); + } + + if (!IS_POSIXACL(realinode)) return NULL; if (rcu) -- 2.25.1
From: Zheng Wang <zyytlz.wz@163.com> mainline inclusion from mainline-v6.3-rc4 commit 6b6bc5b8bd2d4ca9e1efa9ae0f98a0b0687ace75 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I6ZWOL CVE: CVE-2023-2483 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... --------------------------- In emac_probe, &adpt->work_thread is bound with emac_work_thread. Then it will be started by timeout handler emac_tx_timeout or a IRQ handler emac_isr. If we remove the driver which will call emac_remove to make cleanup, there may be a unfinished work. The possible sequence is as follows: Fix it by finishing the work before cleanup in the emac_remove and disable timeout response. CPU0 CPU1 |emac_work_thread emac_remove | free_netdev | kfree(netdev); | |emac_reinit_locked |emac_mac_down |//use netdev Fixes: b9b17debc69d ("net: emac: emac gigabit ethernet controller driver") Signed-off-by: Zheng Wang <zyytlz.wz@163.com> Signed-off-by: David S. Miller <davem@davemloft.net> (cherry picked from commit 6b6bc5b8bd2d4ca9e1efa9ae0f98a0b0687ace75) Signed-off-by: Liu Jian <liujian56@huawei.com> Reviewed-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Wang Weiyang <wangweiyang2@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- drivers/net/ethernet/qualcomm/emac/emac.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/ethernet/qualcomm/emac/emac.c b/drivers/net/ethernet/qualcomm/emac/emac.c index 2a0cbc535a2e..b10f2bcf8506 100644 --- a/drivers/net/ethernet/qualcomm/emac/emac.c +++ b/drivers/net/ethernet/qualcomm/emac/emac.c @@ -741,9 +741,15 @@ static int emac_remove(struct platform_device *pdev) struct net_device *netdev = dev_get_drvdata(&pdev->dev); struct emac_adapter *adpt = netdev_priv(netdev); + netif_carrier_off(netdev); + netif_tx_disable(netdev); + unregister_netdev(netdev); netif_napi_del(&adpt->rx_q.napi); + free_irq(adpt->irq.irq, &adpt->irq); + cancel_work_sync(&adpt->work_thread); + emac_clks_teardown(adpt); put_device(&adpt->phydev->mdio.dev); -- 2.25.1
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Yongqiang Liu