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+f68108fed972453a0ad4@syzkaller.appspotmail.com,
Florian Westphal <fw@strlen.de>,
Pablo Neira Ayuso <pablo@netfilter.org>
Subject: [PATCH 4.14 64/91] netfilter: ebtables: compat: reject all padding in matches/watchers
Date: Thu, 2 Jan 2020 23:07:46 +0100 [thread overview]
Message-ID: <20200102220442.509364885@linuxfoundation.org> (raw)
In-Reply-To: <20200102220356.856162165@linuxfoundation.org>
From: Florian Westphal <fw@strlen.de>
commit e608f631f0ba5f1fc5ee2e260a3a35d13107cbfe upstream.
syzbot reported following splat:
BUG: KASAN: vmalloc-out-of-bounds in size_entry_mwt net/bridge/netfilter/ebtables.c:2063 [inline]
BUG: KASAN: vmalloc-out-of-bounds in compat_copy_entries+0x128b/0x1380 net/bridge/netfilter/ebtables.c:2155
Read of size 4 at addr ffffc900004461f4 by task syz-executor267/7937
CPU: 1 PID: 7937 Comm: syz-executor267 Not tainted 5.5.0-rc1-syzkaller #0
size_entry_mwt net/bridge/netfilter/ebtables.c:2063 [inline]
compat_copy_entries+0x128b/0x1380 net/bridge/netfilter/ebtables.c:2155
compat_do_replace+0x344/0x720 net/bridge/netfilter/ebtables.c:2249
compat_do_ebt_set_ctl+0x22f/0x27e net/bridge/netfilter/ebtables.c:2333
[..]
Because padding isn't considered during computation of ->buf_user_offset,
"total" is decremented by fewer bytes than it should.
Therefore, the first part of
if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
will pass, -- it should not have. This causes oob access:
entry->next_offset is past the vmalloced size.
Reject padding and check that computed user offset (sum of ebt_entry
structure plus all individual matches/watchers/targets) is same
value that userspace gave us as the offset of the next entry.
Reported-by: syzbot+f68108fed972453a0ad4@syzkaller.appspotmail.com
Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bridge/netfilter/ebtables.c | 33 ++++++++++++++++-----------------
1 file changed, 16 insertions(+), 17 deletions(-)
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1876,7 +1876,7 @@ static int ebt_buf_count(struct ebt_entr
}
static int ebt_buf_add(struct ebt_entries_buf_state *state,
- void *data, unsigned int sz)
+ const void *data, unsigned int sz)
{
if (state->buf_kern_start == NULL)
goto count_only;
@@ -1910,7 +1910,7 @@ enum compat_mwt {
EBT_COMPAT_TARGET,
};
-static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt,
+static int compat_mtw_from_user(const struct compat_ebt_entry_mwt *mwt,
enum compat_mwt compat_mwt,
struct ebt_entries_buf_state *state,
const unsigned char *base)
@@ -1986,22 +1986,23 @@ static int compat_mtw_from_user(struct c
/* return size of all matches, watchers or target, including necessary
* alignment and padding.
*/
-static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32,
+static int ebt_size_mwt(const struct compat_ebt_entry_mwt *match32,
unsigned int size_left, enum compat_mwt type,
struct ebt_entries_buf_state *state, const void *base)
{
+ const char *buf = (const char *)match32;
int growth = 0;
- char *buf;
if (size_left == 0)
return 0;
- buf = (char *) match32;
-
- while (size_left >= sizeof(*match32)) {
+ do {
struct ebt_entry_match *match_kern;
int ret;
+ if (size_left < sizeof(*match32))
+ return -EINVAL;
+
match_kern = (struct ebt_entry_match *) state->buf_kern_start;
if (match_kern) {
char *tmp;
@@ -2038,22 +2039,18 @@ static int ebt_size_mwt(struct compat_eb
if (match_kern)
match_kern->match_size = ret;
- /* rule should have no remaining data after target */
- if (type == EBT_COMPAT_TARGET && size_left)
- return -EINVAL;
-
match32 = (struct compat_ebt_entry_mwt *) buf;
- }
+ } while (size_left);
return growth;
}
/* called for all ebt_entry structures. */
-static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,
+static int size_entry_mwt(const struct ebt_entry *entry, const unsigned char *base,
unsigned int *total,
struct ebt_entries_buf_state *state)
{
- unsigned int i, j, startoff, new_offset = 0;
+ unsigned int i, j, startoff, next_expected_off, new_offset = 0;
/* stores match/watchers/targets & offset of next struct ebt_entry: */
unsigned int offsets[4];
unsigned int *offsets_update = NULL;
@@ -2140,11 +2137,13 @@ static int size_entry_mwt(struct ebt_ent
return ret;
}
- startoff = state->buf_user_offset - startoff;
+ next_expected_off = state->buf_user_offset - startoff;
+ if (next_expected_off != entry->next_offset)
+ return -EINVAL;
- if (WARN_ON(*total < startoff))
+ if (*total < entry->next_offset)
return -EINVAL;
- *total -= startoff;
+ *total -= entry->next_offset;
return 0;
}
next prev parent reply other threads:[~2020-01-02 22:50 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-02 22:06 [PATCH 4.14 00/91] 4.14.162-stable review Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 01/91] scsi: lpfc: Fix discovery failures when target device connectivity bounces Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 02/91] scsi: mpt3sas: Fix clear pending bit in ioctl status Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 03/91] scsi: lpfc: Fix locking on mailbox command completion Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 04/91] Input: atmel_mxt_ts - disable IRQ across suspend Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 05/91] iommu/tegra-smmu: Fix page tables in > 4 GiB memory Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 06/91] scsi: target: compare full CHAP_A Algorithm strings Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 07/91] scsi: lpfc: Fix SLI3 hba in loop mode not discovering devices Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 08/91] scsi: csiostor: Dont enable IRQs too early Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 09/91] powerpc/pseries: Mark accumulate_stolen_time() as notrace Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 10/91] powerpc/pseries: Dont fail hash page table insert for bolted mapping Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 11/91] powerpc/tools: Dont quote $objdump in scripts Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 12/91] dma-debug: add a schedule point in debug_dma_dump_mappings() Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 13/91] clocksource/drivers/asm9260: Add a check for of_clk_get Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 14/91] powerpc/security/book3s64: Report L1TF status in sysfs Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 15/91] powerpc/book3s64/hash: Add cond_resched to avoid soft lockup warning Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 16/91] ext4: update direct I/O read lock pattern for IOCB_NOWAIT Greg Kroah-Hartman
2020-01-02 22:06 ` [PATCH 4.14 17/91] jbd2: Fix statistics for the number of logged blocks Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 18/91] scsi: tracing: Fix handling of TRANSFER LENGTH == 0 for READ(6) and WRITE(6) Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 19/91] scsi: lpfc: Fix duplicate unreg_rpi error in port offline flow Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 20/91] f2fs: fix to update dirs i_pino during cross_rename Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 21/91] clk: qcom: Allow constant ratio freq tables for rcg Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 22/91] irqchip/irq-bcm7038-l1: Enable parent IRQ if necessary Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 23/91] irqchip: ingenic: Error out if IRQ domain creation failed Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 24/91] mfd: mfd-core: Honour Device Trees request to disable a child-device Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 25/91] fs/quota: handle overflows of sysctl fs.quota.* and report as unsigned long Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 26/91] scsi: lpfc: fix: Coverity: lpfc_cmpl_els_rsp(): Null pointer dereferences Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 27/91] scsi: ufs: fix potential bug which ends in system hang Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 28/91] powerpc/pseries/cmm: Implement release() function for sysfs device Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 29/91] powerpc/security: Fix wrong message when RFI Flush is disable Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 30/91] scsi: atari_scsi: sun3_scsi: Set sg_tablesize to 1 instead of SG_NONE Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 31/91] clk: pxa: fix one of the pxa RTC clocks Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 32/91] bcache: at least try to shrink 1 node in bch_mca_scan() Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 33/91] HID: logitech-hidpp: Silence intermittent get_battery_capacity errors Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 34/91] libnvdimm/btt: fix variable rc set but not used Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 35/91] HID: Improve Windows Precision Touchpad detection Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 36/91] scsi: pm80xx: Fix for SATA device discovery Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 37/91] scsi: ufs: Fix error handing during hibern8 enter Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 38/91] scsi: scsi_debug: num_tgts must be >= 0 Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 39/91] scsi: NCR5380: Add disconnect_mask module parameter Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 40/91] scsi: iscsi: Dont send data to unbound connection Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 41/91] scsi: target: iscsi: Wait for all commands to finish before freeing a session Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 42/91] gpio: mpc8xxx: Dont overwrite default irq_set_type callback Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 43/91] apparmor: fix unsigned len comparison with less than zero Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 44/91] scripts/kallsyms: fix definitely-lost memory leak Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 45/91] f2fs: choose hardlimit when softlimit is larger than hardlimit in f2fs_statfs_project() Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 46/91] cdrom: respect device capabilities during opening action Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 47/91] perf script: Fix brstackinsn for AUXTRACE Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 48/91] perf regs: Make perf_reg_name() return "unknown" instead of NULL Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 49/91] s390/zcrypt: handle new reply code FILTERED_BY_HYPERVISOR Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 50/91] libfdt: define INT32_MAX and UINT32_MAX in libfdt_env.h Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 51/91] s390/cpum_sf: Check for SDBT and SDB consistency Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 52/91] ocfs2: fix passing zero to PTR_ERR warning Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 53/91] kernel: sysctl: make drop_caches write-only Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 54/91] userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 55/91] x86/mce: Fix possibly incorrect severity calculation on AMD Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 56/91] net, sysctl: Fix compiler warning when only cBPF is present Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 57/91] netfilter: nf_queue: enqueue skbs with NULL dst Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 58/91] ALSA: hda - Downgrade error message for single-cmd fallback Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 59/91] bonding: fix active-backup transition after link failure Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 60/91] perf strbuf: Remove redundant va_end() in strbuf_addv() Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 61/91] Make filldir[64]() verify the directory entry filename is valid Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 62/91] filldir[64]: remove WARN_ON_ONCE() for bad directory entries Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 63/91] PCI/switchtec: Read all 64 bits of part_event_bitmap Greg Kroah-Hartman
2020-01-02 22:07 ` Greg Kroah-Hartman [this message]
2020-01-02 22:07 ` [PATCH 4.14 65/91] 6pack,mkiss: fix possible deadlock Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 66/91] netfilter: bridge: make sure to pull arp header in br_nf_forward_arp() Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 67/91] inetpeer: fix data-race in inet_putpeer / inet_putpeer Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 68/91] net: add a READ_ONCE() in skb_peek_tail() Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 69/91] net: icmp: fix data-race in cmp_global_allow() Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 70/91] hrtimer: Annotate lockless access to timer->state Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 71/91] spi: fsl: dont map irq during probe Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 72/91] tty/serial: atmel: fix out of range clock divider handling Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 73/91] pinctrl: baytrail: Really serialize all register accesses Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 74/91] net: ena: fix napi handler misbehavior when the napi budget is zero Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 75/91] net/mlxfw: Fix out-of-memory error in mfa2 flash burning Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 76/91] ptp: fix the race between the release of ptp_clock and cdev Greg Kroah-Hartman
2020-01-02 22:07 ` [PATCH 4.14 77/91] udp: fix integer overflow while computing available space in sk_rcvbuf Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 78/91] vhost/vsock: accept only packets with the right dst_cid Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 79/91] net: add bool confirm_neigh parameter for dst_ops.update_pmtu Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 80/91] ip6_gre: do not confirm neighbor when do pmtu update Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 81/91] gtp: " Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 82/91] net/dst: add new function skb_dst_update_pmtu_no_confirm Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 83/91] tunnel: do not confirm neighbor when do pmtu update Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 84/91] vti: " Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 85/91] sit: " Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 86/91] gtp: do not allow adding duplicate tid and ms_addr pdp context Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 87/91] tcp/dccp: fix possible race __inet_lookup_established() Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 88/91] tcp: do not send empty skb from tcp_write_xmit() Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 89/91] gtp: fix wrong condition in gtp_genl_dump_pdp() Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 90/91] gtp: fix an use-after-free in ipv4_pdp_find() Greg Kroah-Hartman
2020-01-02 22:08 ` [PATCH 4.14 91/91] gtp: avoid zero size hashtable Greg Kroah-Hartman
2020-01-02 23:05 ` [PATCH 4.14 00/91] 4.14.162-stable review Guenter Roeck
2020-01-03 0:16 ` Sasha Levin
2020-01-03 8:38 ` Greg Kroah-Hartman
2020-01-03 13:43 ` Naresh Kamboju
2020-01-03 14:29 ` Guenter Roeck
2020-01-03 17:50 ` Jon Hunter
2020-01-03 22:01 ` shuah
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