From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
syzbot+7b99aafdcc2eedea6178@syzkaller.appspotmail.com,
Eric Dumazet <edumazet@google.com>,
Marco Elver <elver@google.com>, Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH 4.4 10/30] net: fix up truesize of cloned skb in skb_prepare_for_shift()
Date: Fri, 5 Mar 2021 13:22:39 +0100 [thread overview]
Message-ID: <20210305120849.909910163@linuxfoundation.org> (raw)
In-Reply-To: <20210305120849.381261651@linuxfoundation.org>
From: Marco Elver <elver@google.com>
commit 097b9146c0e26aabaa6ff3e5ea536a53f5254a79 upstream.
Avoid the assumption that ksize(kmalloc(S)) == ksize(kmalloc(S)): when
cloning an skb, save and restore truesize after pskb_expand_head(). This
can occur if the allocator decides to service an allocation of the same
size differently (e.g. use a different size class, or pass the
allocation on to KFENCE).
Because truesize is used for bookkeeping (such as sk_wmem_queued), a
modified truesize of a cloned skb may result in corrupt bookkeeping and
relevant warnings (such as in sk_stream_kill_queues()).
Link: https://lkml.kernel.org/r/X9JR/J6dMMOy1obu@elver.google.com
Reported-by: syzbot+7b99aafdcc2eedea6178@syzkaller.appspotmail.com
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210201160420.2826895-1-elver@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/core/skbuff.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2628,7 +2628,19 @@ EXPORT_SYMBOL(skb_split);
*/
static int skb_prepare_for_shift(struct sk_buff *skb)
{
- return skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+ int ret = 0;
+
+ if (skb_cloned(skb)) {
+ /* Save and restore truesize: pskb_expand_head() may reallocate
+ * memory where ksize(kmalloc(S)) != ksize(kmalloc(S)), but we
+ * cannot change truesize at this point.
+ */
+ unsigned int save_truesize = skb->truesize;
+
+ ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+ skb->truesize = save_truesize;
+ }
+ return ret;
}
/**
next prev parent reply other threads:[~2021-03-05 12:43 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 12:22 [PATCH 4.4 00/30] 4.4.260-rc1 review Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 01/30] futex: Ensure the correct return value from futex_lock_pi() Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 02/30] net: usb: qmi_wwan: support ZTE P685M modem Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 03/30] iwlwifi: pcie: fix to correct null check Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 04/30] mmc: sdhci-esdhc-imx: fix kernel panic when remove module Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 05/30] scripts: use pkg-config to locate libcrypto Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 06/30] scripts: set proper OpenSSL include dir also for sign-file Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 07/30] hugetlb: fix update_and_free_page contig page struct assumption Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 08/30] JFS: more checks for invalid superblock Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 09/30] xfs: Fix assert failure in xfs_setattr_size() Greg Kroah-Hartman
2021-03-05 12:22 ` Greg Kroah-Hartman [this message]
2021-03-05 12:22 ` [PATCH 4.4 11/30] mm/hugetlb.c: fix unnecessary address expansion of pmd sharing Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 12/30] staging: fwserial: Fix error handling in fwserial_create Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 13/30] x86/reboot: Add Zotac ZBOX CI327 nano PCI reboot quirk Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 14/30] vt/consolemap: do font sum unsigned Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 15/30] wlcore: Fix command execute failure 19 for wl12xx Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 16/30] pktgen: fix misuse of BUG_ON() in pktgen_thread_worker() Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 17/30] ath10k: fix wmi mgmt tx queue full due to race condition Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 18/30] x86/build: Treat R_386_PLT32 relocation as R_386_PC32 Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 19/30] Bluetooth: Fix null pointer dereference in amp_read_loc_assoc_final_data Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 20/30] staging: most: sound: add sanity check for function argument Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 21/30] media: uvcvideo: Allow entities with no pads Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 22/30] scsi: iscsi: Restrict sessions and handles to admin capabilities Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 23/30] sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 24/30] scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 25/30] scsi: iscsi: Verify lengths on passthrough PDUs Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 26/30] Xen/gnttab: handle p2m update errors on a per-slot basis Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 27/30] xen-netback: respect gnttab_map_refs()s return value Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 28/30] zsmalloc: account the number of compacted pages correctly Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 29/30] swap: fix swapfile read/write offset Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.4 30/30] media: v4l: ioctl: Fix memory leak in video_usercopy Greg Kroah-Hartman
2021-03-05 22:06 ` [PATCH 4.4 00/30] 4.4.260-rc1 review Pavel Machek
2021-03-06 8:08 ` Greg Kroah-Hartman
2021-03-06 23:07 ` Pavel Machek
2021-03-07 0:04 ` qemu meltdown test failure was " Pavel Machek
2021-03-07 8:20 ` Pavel Machek
2021-03-07 20:18 ` Pavel Machek
2021-03-06 10:40 ` Naresh Kamboju
2021-03-06 16:27 ` Guenter Roeck
2021-03-06 16:30 ` Guenter Roeck
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