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 4.9 21/41] net: fix up truesize of cloned skb in skb_prepare_for_shift()
Date: Fri, 5 Mar 2021 13:22:28 +0100 [thread overview]
Message-ID: <20210305120852.339523244@linuxfoundation.org> (raw)
In-Reply-To: <20210305120851.255002428@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
@@ -2673,7 +2673,19 @@ 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: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 12:22 [PATCH 4.9 00/41] 4.9.260-rc1 review Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 01/41] futex: Cleanup variable names for futex_top_waiter() Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 02/41] futex: Cleanup refcounting Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 03/41] futex: Pull rt_mutex_futex_unlock() out from under hb->lock Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 04/41] futex: Futex_unlock_pi() determinism Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 05/41] futex: Fix pi_state->owner serialization Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 06/41] futex: Fix more put_pi_state() vs. exit_pi_state_list() races Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 07/41] futex: Dont enable IRQs unconditionally in put_pi_state() Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 08/41] net: usb: qmi_wwan: support ZTE P685M modem Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 09/41] arm: kprobes: Allow to handle reentered kprobe on single-stepping Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 10/41] scripts: use pkg-config to locate libcrypto Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 11/41] scripts: set proper OpenSSL include dir also for sign-file Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 12/41] hugetlb: fix update_and_free_page contig page struct assumption Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 13/41] printk: fix deadlock when kernel panic Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 14/41] arm64: Remove redundant mov from LL/SC cmpxchg Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 15/41] arm64: Avoid redundant type conversions in xchg() and cmpxchg() Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 16/41] arm64: cmpxchg: Use "K" instead of "L" for ll/sc immediate constraint Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 17/41] arm64: Use correct ll/sc atomic constraints Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 18/41] JFS: more checks for invalid superblock Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 19/41] xfs: Fix assert failure in xfs_setattr_size() Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 20/41] smackfs: restrict bytes count in smackfs write functions Greg Kroah-Hartman
2021-03-05 12:22 ` Greg Kroah-Hartman [this message]
2021-03-05 12:22 ` [PATCH 4.9 22/41] mm/hugetlb.c: fix unnecessary address expansion of pmd sharing Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 23/41] staging: fwserial: Fix error handling in fwserial_create Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 24/41] x86/reboot: Add Zotac ZBOX CI327 nano PCI reboot quirk Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 25/41] vt/consolemap: do font sum unsigned Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 26/41] wlcore: Fix command execute failure 19 for wl12xx Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 27/41] pktgen: fix misuse of BUG_ON() in pktgen_thread_worker() Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 28/41] ath10k: fix wmi mgmt tx queue full due to race condition Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 29/41] x86/build: Treat R_386_PLT32 relocation as R_386_PC32 Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 30/41] Bluetooth: Fix null pointer dereference in amp_read_loc_assoc_final_data Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 31/41] staging: most: sound: add sanity check for function argument Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 32/41] media: uvcvideo: Allow entities with no pads Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 33/41] scsi: iscsi: Restrict sessions and handles to admin capabilities Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 34/41] sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 35/41] scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 36/41] scsi: iscsi: Verify lengths on passthrough PDUs Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 37/41] Xen/gnttab: handle p2m update errors on a per-slot basis Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 38/41] xen-netback: respect gnttab_map_refs()s return value Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 39/41] zsmalloc: account the number of compacted pages correctly Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 40/41] swap: fix swapfile read/write offset Greg Kroah-Hartman
2021-03-05 12:22 ` [PATCH 4.9 41/41] media: v4l: ioctl: Fix memory leak in video_usercopy Greg Kroah-Hartman
2021-03-06 5:16 ` [PATCH 4.9 00/41] 4.9.260-rc1 review Florian Fainelli
2021-03-06 16:29 ` Guenter Roeck
2021-03-06 16:30 ` Guenter Roeck
2021-03-07 2:26 ` Naresh Kamboju
2021-03-12 20:24 ` Florian Fainelli
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