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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	Aleksandr Yashkin <a.yashkin@inango-systems.com>,
	Nikolay Merinov <n.merinov@inango-systems.com>,
	Ariel Gilman <a.gilman@inango-systems.com>,
	Kees Cook <keescook@chromium.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.4 33/59] pstore/ram: Write new dumps to start of recycled zones
Date: Sat, 11 Jan 2020 10:49:42 +0100	[thread overview]
Message-ID: <20200111094844.943026669@linuxfoundation.org> (raw)
In-Reply-To: <20200111094835.417654274@linuxfoundation.org>

From: Aleksandr Yashkin <a.yashkin@inango-systems.com>

[ Upstream commit 9e5f1c19800b808a37fb9815a26d382132c26c3d ]

The ram_core.c routines treat przs as circular buffers. When writing a
new crash dump, the old buffer needs to be cleared so that the new dump
doesn't end up in the wrong place (i.e. at the end).

The solution to this problem is to reset the circular buffer state before
writing a new Oops dump.

Signed-off-by: Aleksandr Yashkin <a.yashkin@inango-systems.com>
Signed-off-by: Nikolay Merinov <n.merinov@inango-systems.com>
Signed-off-by: Ariel Gilman <a.gilman@inango-systems.com>
Link: https://lore.kernel.org/r/20191223133816.28155-1-n.merinov@inango-systems.com
Fixes: 896fc1f0c4c6 ("pstore/ram: Switch to persistent_ram routines")
[kees: backport to v4.9]
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/pstore/ram.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 59d93acc29c7..fa0e89edb62d 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -319,6 +319,17 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
 
 	prz = cxt->przs[cxt->dump_write_cnt];
 
+	/*
+	 * Since this is a new crash dump, we need to reset the buffer in
+	 * case it still has an old dump present. Without this, the new dump
+	 * will get appended, which would seriously confuse anything trying
+	 * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
+	 * expects to find a dump header in the beginning of buffer data, so
+	 * we must to reset the buffer values, in order to ensure that the
+	 * header will be written to the beginning of the buffer.
+	 */
+	persistent_ram_zap(prz);
+
 	hlen = ramoops_write_kmsg_hdr(prz, compressed);
 	if (size + hlen > prz->buffer_size)
 		size = prz->buffer_size - hlen;
-- 
2.20.1




  parent reply	other threads:[~2020-01-11  9:54 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-11  9:49 [PATCH 4.4 00/59] 4.4.209-stable review Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 01/59] PM / devfreq: Dont fail devfreq_dev_release if not in list Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 02/59] RDMA/cma: add missed unregister_pernet_subsys in init failure Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 03/59] scsi: lpfc: Fix memory leak on lpfc_bsg_write_ebuf_set func Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 04/59] scsi: qla2xxx: Dont call qlt_async_event twice Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 05/59] scsi: iscsi: qla4xxx: fix double free in probe Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 06/59] scsi: libsas: stop discovering if oob mode is disconnected Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 07/59] usb: gadget: fix wrong endpoint desc Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 08/59] md: raid1: check rdev before reference in raid1_sync_request func Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 09/59] s390/cpum_sf: Adjust sampling interval to avoid hitting sample limits Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 10/59] s390/cpum_sf: Avoid SBD overflow condition in irq handler Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 11/59] xen/balloon: fix ballooned page accounting without hotplug enabled Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 12/59] xfs: fix mount failure crash on invalid iclog memory access Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 13/59] taskstats: fix data-race Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 14/59] Revert "perf report: Add warning when libunwind not compiled in" Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 15/59] ALSA: ice1724: Fix sleep-in-atomic in Infrasonic Quartet support code Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 16/59] MIPS: Avoid VDSO ABI breakage due to global register variable Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 17/59] locks: print unsigned ino in /proc/locks Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 18/59] dmaengine: Fix access to uninitialized dma_slave_caps Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 19/59] compat_ioctl: block: handle Persistent Reservations Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 20/59] gpiolib: fix up emulated open drain outputs Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 21/59] ALSA: cs4236: fix error return comparison of an unsigned integer Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 22/59] ftrace: Avoid potential division by zero in function profiler Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 23/59] Bluetooth: btusb: fix PM leak in error case of setup Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 24/59] Bluetooth: delete a stray unlock Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 25/59] tty: serial: msm_serial: Fix lockup for sysrq and oops Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 26/59] drm/mst: Fix MST sideband up-reply failure handling Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 27/59] powerpc/pseries/hvconsole: Fix stack overread via udbg Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 28/59] ath9k_htc: Modify byte order for an error message Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 29/59] ath9k_htc: Discard undersized packets Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 30/59] net: add annotations on hh->hh_len lockless accesses Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 31/59] s390/smp: fix physical to logical CPU map for SMT Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 32/59] locking/x86: Remove the unused atomic_inc_short() methd Greg Kroah-Hartman
2020-01-11  9:49 ` Greg Kroah-Hartman [this message]
2020-01-11  9:49 ` [PATCH 4.4 34/59] locking/spinlock/debug: Fix various data races Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 35/59] netfilter: ctnetlink: netns exit must wait for callbacks Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 36/59] ARM: vexpress: Set-up shared OPP table instead of individual for each CPU Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 37/59] netfilter: uapi: Avoid undefined left-shift in xt_sctp.h Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 38/59] ARM: dts: am437x-gp/epos-evm: fix panel compatible Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 39/59] powerpc: Ensure that swiotlb buffer is allocated from low memory Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 40/59] bnx2x: Do not handle requests from VFs after parity Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 41/59] bnx2x: Fix logic to get total no. of PFs per engine Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 42/59] net: usb: lan78xx: Fix error message format specifier Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 43/59] rfkill: Fix incorrect check to avoid NULL pointer dereference Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 44/59] ASoC: wm8962: fix lambda value Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 45/59] regulator: rn5t618: fix module aliases Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 46/59] kconfig: dont crash on NULL expressions in expr_eq() Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 47/59] parisc: Fix compiler warnings in debug_core.c Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 48/59] llc2: Fix return statement of llc_stat_ev_rx_null_dsap_xid_c (and _test_c) Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 49/59] net: stmmac: dwmac-sunxi: Allow all RGMII modes Greg Kroah-Hartman
2020-01-11  9:49 ` [PATCH 4.4 50/59] net: usb: lan78xx: fix possible skb leak Greg Kroah-Hartman
2020-01-11  9:50 ` [PATCH 4.4 51/59] pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM Greg Kroah-Hartman
2020-01-11  9:50 ` [PATCH 4.4 52/59] sctp: free cmd->obj.chunk for the unprocessed SCTP_CMD_REPLY Greg Kroah-Hartman
2020-01-11  9:50 ` [PATCH 4.4 53/59] tcp: fix "old stuff" D-SACK causing SACK to be treated as D-SACK Greg Kroah-Hartman
2020-01-11  9:50 ` [PATCH 4.4 54/59] vlan: vlan_changelink() should propagate errors Greg Kroah-Hartman
2020-01-11  9:50 ` [PATCH 4.4 55/59] vlan: fix memory leak in vlan_dev_set_egress_priority Greg Kroah-Hartman
2020-01-11  9:50 ` [PATCH 4.4 56/59] vxlan: fix tos value before xmit Greg Kroah-Hartman
2020-01-11  9:50 ` [PATCH 4.4 57/59] macvlan: do not assume mac_header is set in macvlan_broadcast() Greg Kroah-Hartman
2020-01-11  9:50 ` [PATCH 4.4 58/59] USB: core: fix check for duplicate endpoints Greg Kroah-Hartman
2020-01-11  9:50 ` [PATCH 4.4 59/59] USB: serial: option: add Telit ME910G1 0x110a composition Greg Kroah-Hartman
2020-01-11 14:51 ` [PATCH 4.4 00/59] 4.4.209-stable review Guenter Roeck
2020-01-11 18:39 ` Naresh Kamboju
2020-01-13 15:41 ` Jon Hunter
2020-01-13 15:41   ` Jon Hunter

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