From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH 4.9 18/54] epoll: do not insert into poll queues until all sanity checks are done
Date: Mon, 12 Oct 2020 15:26:40 +0200 [thread overview]
Message-ID: <20201012132630.437902095@linuxfoundation.org> (raw)
In-Reply-To: <20201012132629.585664421@linuxfoundation.org>
From: Al Viro <viro@zeniv.linux.org.uk>
commit f8d4f44df056c5b504b0d49683fb7279218fd207 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/eventpoll.c | 37 ++++++++++++++++++-------------------
1 file changed, 18 insertions(+), 19 deletions(-)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1332,6 +1332,22 @@ static int ep_insert(struct eventpoll *e
RCU_INIT_POINTER(epi->ws, NULL);
}
+ /* Add the current item to the list of active epoll hook for this file */
+ spin_lock(&tfile->f_lock);
+ list_add_tail_rcu(&epi->fllink, &tfile->f_ep_links);
+ spin_unlock(&tfile->f_lock);
+
+ /*
+ * Add the current item to the RB tree. All RB tree operations are
+ * protected by "mtx", and ep_insert() is called with "mtx" held.
+ */
+ ep_rbtree_insert(ep, epi);
+
+ /* now check if we've created too many backpaths */
+ error = -EINVAL;
+ if (full_check && reverse_path_check())
+ goto error_remove_epi;
+
/* Initialize the poll table using the queue callback */
epq.epi = epi;
init_poll_funcptr(&epq.pt, ep_ptable_queue_proc);
@@ -1354,22 +1370,6 @@ static int ep_insert(struct eventpoll *e
if (epi->nwait < 0)
goto error_unregister;
- /* Add the current item to the list of active epoll hook for this file */
- spin_lock(&tfile->f_lock);
- list_add_tail_rcu(&epi->fllink, &tfile->f_ep_links);
- spin_unlock(&tfile->f_lock);
-
- /*
- * Add the current item to the RB tree. All RB tree operations are
- * protected by "mtx", and ep_insert() is called with "mtx" held.
- */
- ep_rbtree_insert(ep, epi);
-
- /* now check if we've created too many backpaths */
- error = -EINVAL;
- if (full_check && reverse_path_check())
- goto error_remove_epi;
-
/* We have to drop the new item inside our item list to keep track of it */
spin_lock_irqsave(&ep->lock, flags);
@@ -1395,6 +1395,8 @@ static int ep_insert(struct eventpoll *e
return 0;
+error_unregister:
+ ep_unregister_pollwait(ep, epi);
error_remove_epi:
spin_lock(&tfile->f_lock);
list_del_rcu(&epi->fllink);
@@ -1402,9 +1404,6 @@ error_remove_epi:
rb_erase(&epi->rbn, &ep->rbr);
-error_unregister:
- ep_unregister_pollwait(ep, epi);
-
/*
* We need to do this because an event could have been arrived on some
* allocated wait queue. Note that we don't care about the ep->ovflist
next prev parent reply other threads:[~2020-10-12 14:05 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-12 13:26 [PATCH 4.9 00/54] 4.9.239-rc1 review Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 01/54] vsock/virtio: use RCU to avoid use-after-free on the_virtio_vsock Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 02/54] vsock/virtio: stop workers during the .remove() Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 03/54] USB: gadget: f_ncm: Fix NDP16 datagram validation Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 04/54] gpio: tc35894: fix up tc35894 interrupt configuration Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 05/54] Input: i8042 - add nopnp quirk for Acer Aspire 5 A515 Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 06/54] drm/amdgpu: restore proper ref count in amdgpu_display_crtc_set_config Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 07/54] net: dec: de2104x: Increase receive ring size for Tulip Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 08/54] rndis_host: increase sleep time in the query-response loop Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 09/54] drivers/net/wan/lapbether: Make skb->protocol consistent with the header Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 10/54] drivers/net/wan/hdlc: Set skb->protocol before transmitting Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 11/54] mac80211: do not allow bigger VHT MPDUs than the hardware supports Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 12/54] nfs: Fix security label length not being reset Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 13/54] clk: samsung: exynos4: mark chipid clock as CLK_IGNORE_UNUSED Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 14/54] iommu/exynos: add missing put_device() call in exynos_iommu_of_xlate() Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 15/54] i2c: cpm: Fix i2c_ram structure Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 16/54] random32: Restore __latent_entropy attribute on net_rand_state Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 17/54] net/packet: fix overflow in tpacket_rcv Greg Kroah-Hartman
2020-10-12 13:26 ` Greg Kroah-Hartman [this message]
2020-10-12 13:26 ` [PATCH 4.9 19/54] epoll: replace ->visited/visited_list with generation count Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 20/54] epoll: EPOLL_CTL_ADD: close the race in decision to take fast path Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 21/54] ep_create_wakeup_source(): dentry name can change under you Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 22/54] netfilter: ctnetlink: add a range check for l3/l4 protonum Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 23/54] fbdev, newport_con: Move FONT_EXTRA_WORDS macros into linux/font.h Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 24/54] Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 25/54] Revert "ravb: Fixed to be able to unload modules" Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 26/54] fbcon: Fix global-out-of-bounds read in fbcon_get_font() Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 27/54] net: wireless: nl80211: fix out-of-bounds access in nl80211_del_key() Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 28/54] usermodehelper: reset umask to default before executing user process Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 29/54] platform/x86: thinkpad_acpi: initialize tp_nvram_state variable Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 30/54] platform/x86: thinkpad_acpi: re-initialize ACPI buffer size when reuse Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 31/54] driver core: Fix probe_count imbalance in really_probe() Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 32/54] perf top: Fix stdio interface input handling with glibc 2.28+ Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 33/54] mtd: rawnand: sunxi: Fix the probe error path Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 34/54] ftrace: Move RCU is watching check after recursion check Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 35/54] macsec: avoid use-after-free in macsec_handle_frame() Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 36/54] mm/khugepaged: fix filemap page_to_pgoff(page) != offset Greg Kroah-Hartman
2020-10-12 13:26 ` [PATCH 4.9 37/54] sctp: fix sctp_auth_init_hmacs() error path Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 38/54] team: set dev->needed_headroom in team_setup_by_port() Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 39/54] net: team: fix memory leak in __team_options_register Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 40/54] openvswitch: handle DNAT tuple collision Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 41/54] drm/amdgpu: prevent double kfree ttm->sg Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 42/54] xfrm: clone XFRMA_REPLAY_ESN_VAL in xfrm_do_migrate Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 43/54] xfrm: clone whole liftime_cur structure " Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 44/54] net: stmmac: removed enabling eee in EEE set callback Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 45/54] xfrm: Use correct address family in xfrm_state_find Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 46/54] bonding: set dev->needed_headroom in bond_setup_by_slave() Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 47/54] mdio: fix mdio-thunder.c dependency & build error Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 48/54] rxrpc: Fix rxkad token xdr encoding Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 49/54] rxrpc: Downgrade the BUG() for unsupported token type in rxrpc_read() Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 50/54] rxrpc: Fix some missing _bh annotations on locking conn->state_lock Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 51/54] rxrpc: Fix server keyring leak Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 52/54] perf: Fix task_function_call() error handling Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 53/54] mm: khugepaged: recalculate min_free_kbytes after memory hotplug as expected by khugepaged Greg Kroah-Hartman
2020-10-12 13:27 ` [PATCH 4.9 54/54] net: usb: rtl8150: set random MAC address when set_ethernet_addr() fails Greg Kroah-Hartman
2020-10-13 6:34 ` [PATCH 4.9 00/54] 4.9.239-rc1 review Naresh Kamboju
2020-10-13 16:39 ` Guenter Roeck
2020-10-14 1:39 ` Shuah Khan
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