From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Ben England <bengland@redhat.com>,
Jeff Layton <jlayton@kernel.org>, "Yan, Zheng" <zyan@redhat.com>,
Ilya Dryomov <idryomov@gmail.com>
Subject: [PATCH 5.0 27/89] ceph: only use d_name directly when parent is locked
Date: Tue, 30 Apr 2019 13:38:18 +0200 [thread overview]
Message-ID: <20190430113611.254977922@linuxfoundation.org> (raw)
In-Reply-To: <20190430113609.741196396@linuxfoundation.org>
From: Jeff Layton <jlayton@kernel.org>
commit 1bcb344086f3ecf8d6705f6d708441baa823beb3 upstream.
Ben reported tripping the BUG_ON in create_request_message during some
performance testing. Analysis of the vmcore showed that the length of
the r_dentry->d_name string changed after we allocated the buffer, but
before we encoded it.
build_dentry_path returns pointers to d_name in the common case of
non-snapped dentries, but this optimization isn't safe unless the parent
directory is locked. When it isn't, have the code make a copy of the
d_name while holding the d_lock.
Cc: stable@vger.kernel.org
Reported-by: Ben England <bengland@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ceph/mds_client.c | 61 +++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 50 insertions(+), 11 deletions(-)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1958,10 +1958,39 @@ retry:
return path;
}
+/* Duplicate the dentry->d_name.name safely */
+static int clone_dentry_name(struct dentry *dentry, const char **ppath,
+ int *ppathlen)
+{
+ u32 len;
+ char *name;
+
+retry:
+ len = READ_ONCE(dentry->d_name.len);
+ name = kmalloc(len + 1, GFP_NOFS);
+ if (!name)
+ return -ENOMEM;
+
+ spin_lock(&dentry->d_lock);
+ if (dentry->d_name.len != len) {
+ spin_unlock(&dentry->d_lock);
+ kfree(name);
+ goto retry;
+ }
+ memcpy(name, dentry->d_name.name, len);
+ spin_unlock(&dentry->d_lock);
+
+ name[len] = '\0';
+ *ppath = name;
+ *ppathlen = len;
+ return 0;
+}
+
static int build_dentry_path(struct dentry *dentry, struct inode *dir,
const char **ppath, int *ppathlen, u64 *pino,
- int *pfreepath)
+ bool *pfreepath, bool parent_locked)
{
+ int ret;
char *path;
rcu_read_lock();
@@ -1970,8 +1999,15 @@ static int build_dentry_path(struct dent
if (dir && ceph_snap(dir) == CEPH_NOSNAP) {
*pino = ceph_ino(dir);
rcu_read_unlock();
- *ppath = dentry->d_name.name;
- *ppathlen = dentry->d_name.len;
+ if (parent_locked) {
+ *ppath = dentry->d_name.name;
+ *ppathlen = dentry->d_name.len;
+ } else {
+ ret = clone_dentry_name(dentry, ppath, ppathlen);
+ if (ret)
+ return ret;
+ *pfreepath = true;
+ }
return 0;
}
rcu_read_unlock();
@@ -1979,13 +2015,13 @@ static int build_dentry_path(struct dent
if (IS_ERR(path))
return PTR_ERR(path);
*ppath = path;
- *pfreepath = 1;
+ *pfreepath = true;
return 0;
}
static int build_inode_path(struct inode *inode,
const char **ppath, int *ppathlen, u64 *pino,
- int *pfreepath)
+ bool *pfreepath)
{
struct dentry *dentry;
char *path;
@@ -2001,7 +2037,7 @@ static int build_inode_path(struct inode
if (IS_ERR(path))
return PTR_ERR(path);
*ppath = path;
- *pfreepath = 1;
+ *pfreepath = true;
return 0;
}
@@ -2012,7 +2048,7 @@ static int build_inode_path(struct inode
static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
struct inode *rdiri, const char *rpath,
u64 rino, const char **ppath, int *pathlen,
- u64 *ino, int *freepath)
+ u64 *ino, bool *freepath, bool parent_locked)
{
int r = 0;
@@ -2022,7 +2058,7 @@ static int set_request_path_attr(struct
ceph_snap(rinode));
} else if (rdentry) {
r = build_dentry_path(rdentry, rdiri, ppath, pathlen, ino,
- freepath);
+ freepath, parent_locked);
dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
*ppath);
} else if (rpath || rino) {
@@ -2048,7 +2084,7 @@ static struct ceph_msg *create_request_m
const char *path2 = NULL;
u64 ino1 = 0, ino2 = 0;
int pathlen1 = 0, pathlen2 = 0;
- int freepath1 = 0, freepath2 = 0;
+ bool freepath1 = false, freepath2 = false;
int len;
u16 releases;
void *p, *end;
@@ -2056,16 +2092,19 @@ static struct ceph_msg *create_request_m
ret = set_request_path_attr(req->r_inode, req->r_dentry,
req->r_parent, req->r_path1, req->r_ino1.ino,
- &path1, &pathlen1, &ino1, &freepath1);
+ &path1, &pathlen1, &ino1, &freepath1,
+ test_bit(CEPH_MDS_R_PARENT_LOCKED,
+ &req->r_req_flags));
if (ret < 0) {
msg = ERR_PTR(ret);
goto out;
}
+ /* If r_old_dentry is set, then assume that its parent is locked */
ret = set_request_path_attr(NULL, req->r_old_dentry,
req->r_old_dentry_dir,
req->r_path2, req->r_ino2.ino,
- &path2, &pathlen2, &ino2, &freepath2);
+ &path2, &pathlen2, &ino2, &freepath2, true);
if (ret < 0) {
msg = ERR_PTR(ret);
goto out_free1;
next prev parent reply other threads:[~2019-04-30 11:48 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-30 11:37 [PATCH 5.0 00/89] 5.0.11-stable review Greg Kroah-Hartman
2019-04-30 11:37 ` [PATCH 5.0 01/89] netfilter: nf_tables: bogus EBUSY when deleting set after flush Greg Kroah-Hartman
2019-04-30 11:37 ` [PATCH 5.0 02/89] netfilter: nf_tables: bogus EBUSY in helper removal from transaction Greg Kroah-Hartman
2019-04-30 11:37 ` [PATCH 5.0 03/89] intel_th: gth: Fix an off-by-one in output unassigning Greg Kroah-Hartman
2019-04-30 11:37 ` [PATCH 5.0 04/89] powerpc/vdso32: fix CLOCK_MONOTONIC on PPC64 Greg Kroah-Hartman
2019-04-30 11:37 ` [PATCH 5.0 05/89] ALSA: hda/realtek - Move to ACT_INIT state Greg Kroah-Hartman
2019-04-30 11:37 ` [PATCH 5.0 06/89] fs/proc/proc_sysctl.c: Fix a NULL pointer dereference Greg Kroah-Hartman
2019-04-30 11:37 ` [PATCH 5.0 07/89] block, bfq: fix use after free in bfq_bfqq_expire Greg Kroah-Hartman
2019-04-30 11:37 ` [PATCH 5.0 08/89] cifs: fix memory leak in SMB2_read Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 09/89] cifs: fix page reference leak with readv/writev Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 10/89] cifs: do not attempt cifs operation on smb2+ rename error Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 11/89] tracing: Fix a memory leak by early error exit in trace_pid_write() Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 12/89] tracing: Fix buffer_ref pipe ops Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 13/89] crypto: xts - Fix atomic sleep when walking skcipher Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 14/89] crypto: lrw " Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 15/89] gpio: eic: sprd: Fix incorrect irq type setting for the sync EIC Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 16/89] zram: pass down the bvec we need to read into in the work struct Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 17/89] lib/Kconfig.debug: fix build error without CONFIG_BLOCK Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 18/89] MIPS: scall64-o32: Fix indirect syscall number load Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 19/89] trace: Fix preempt_enable_no_resched() abuse Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 20/89] mm: do not boost watermarks to avoid fragmentation for the DISCONTIG memory model Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 21/89] arm64: mm: Ensure tail of unaligned initrd is reserved Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 22/89] IB/rdmavt: Fix frwr memory registration Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 23/89] RDMA/mlx5: Do not allow the user to write to the clock page Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 24/89] RDMA/mlx5: Use rdma_user_map_io for mapping BAR pages Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 25/89] RDMA/ucontext: Fix regression with disassociate Greg Kroah-Hartman
2019-05-03 11:47 ` Michal Kubecek
2019-05-03 11:48 ` Michal Kubecek
2019-04-30 11:38 ` [PATCH 5.0 26/89] sched/numa: Fix a possible divide-by-zero Greg Kroah-Hartman
2019-04-30 11:38 ` Greg Kroah-Hartman [this message]
2019-04-30 11:38 ` [PATCH 5.0 28/89] ceph: ensure d_name stability in ceph_dentry_hash() Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 29/89] ceph: fix ci->i_head_snapc leak Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 30/89] nfsd: Dont release the callback slot unless it was actually held Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 31/89] nfsd: wake waiters blocked on file_lock before deleting it Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 32/89] nfsd: wake blocked file lock waiters before sending callback Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 33/89] sunrpc: dont mark uninitialised items as VALID Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 34/89] perf/x86/intel: Update KBL Package C-state events to also include PC8/PC9/PC10 counters Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 35/89] Input: synaptics-rmi4 - write config register values to the right offset Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 36/89] vfio/type1: Limit DMA mappings per container Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 37/89] dmaengine: sh: rcar-dmac: With cyclic DMA residue 0 is valid Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 38/89] dmaengine: sh: rcar-dmac: Fix glitch in dmaengine_tx_status Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 39/89] dmaengine: mediatek-cqdma: fix wrong register usage in mtk_cqdma_start Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 40/89] ARM: 8857/1: efi: enable CP15 DMB instructions before cleaning the cache Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 41/89] powerpc/mm/radix: Make Radix require HUGETLB_PAGE Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 42/89] drm/vc4: Fix memory leak during gpu reset Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 43/89] drm/ttm: fix re-init of global structures Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 44/89] Revert "drm/i915/fbdev: Actually configure untiled displays" Greg Kroah-Hartman
2019-05-01 13:02 ` Sasha Levin
2019-05-01 13:06 ` Sasha Levin
2019-05-01 13:08 ` Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 45/89] drm/vc4: Fix compilation error reported by kbuild test bot Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 46/89] USB: Add new USB LPM helpers Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 47/89] USB: Consolidate LPM checks to avoid enabling LPM twice Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 48/89] ext4: fix some error pointer dereferences Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 49/89] loop: do not print warn message if partition scan is successful Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 50/89] tipc: handle the err returned from cmd header function Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 51/89] slip: make slhc_free() silently accept an error pointer Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 52/89] workqueue: Try to catch flush_work() without INIT_WORK() Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 53/89] binder: fix handling of misaligned binder object Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 54/89] sched/deadline: Correctly handle active 0-lag timers Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 55/89] mac80211_hwsim: calculate if_combination.max_interfaces Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 56/89] NFS: Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 57/89] netfilter: ebtables: CONFIG_COMPAT: drop a bogus WARN_ON Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 58/89] fm10k: Fix a potential NULL pointer dereference Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 59/89] tipc: check bearer name with right length in tipc_nl_compat_bearer_enable Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 60/89] tipc: check link name with right length in tipc_nl_compat_link_set Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 61/89] net: netrom: Fix error cleanup path of nr_proto_init Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 62/89] net/rds: Check address length before reading address family Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 63/89] rxrpc: fix race condition in rxrpc_input_packet() Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 64/89] pin iocb through aio Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 65/89] aio: fold lookup_kiocb() into its sole caller Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 66/89] aio: keep io_event in aio_kiocb Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 67/89] aio: store event at final iocb_put() Greg Kroah-Hartman
2019-04-30 11:38 ` [PATCH 5.0 68/89] Fix aio_poll() races Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 69/89] x86, retpolines: Raise limit for generating indirect calls from switch-case Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 70/89] x86/retpolines: Disable switch jump tables when retpolines are enabled Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 71/89] rdma: fix build errors on s390 and MIPS due to bad ZERO_PAGE use Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 72/89] ipv4: add sanity checks in ipv4_link_failure() Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 73/89] ipv4: set the tcp_min_rtt_wlen range from 0 to one day Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 74/89] mlxsw: spectrum: Fix autoneg status in ethtool Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 75/89] net/mlx5e: ethtool, Remove unsupported SFP EEPROM high pages query Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 76/89] net: rds: exchange of 8K and 1M pool Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 77/89] net/rose: fix unbound loop in rose_loopback_timer() Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 78/89] net: stmmac: move stmmac_check_ether_addr() to driver probe Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 79/89] net/tls: fix refcount adjustment in fallback Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 80/89] stmmac: pci: Adjust IOT2000 matching Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 81/89] team: fix possible recursive locking when add slaves Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 82/89] net: socionext: replace napi_alloc_frag with the netdev variant on init Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 83/89] net/ncsi: handle overflow when incrementing mac address Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 84/89] mlxsw: pci: Reincrease PCI reset timeout Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 85/89] mlxsw: spectrum: Put MC TCs into DWRR mode Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 86/89] net/mlx5e: Fix the max MTU check in case of XDP Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 87/89] net/mlx5e: Fix use-after-free after xdp_return_frame Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 88/89] net/tls: avoid potential deadlock in tls_set_device_offload_rx() Greg Kroah-Hartman
2019-04-30 11:39 ` [PATCH 5.0 89/89] net/tls: dont leak IV and record seq when offload fails Greg Kroah-Hartman
2019-04-30 17:06 ` [PATCH 5.0 00/89] 5.0.11-stable review kernelci.org bot
2019-04-30 22:33 ` shuah
2019-05-01 7:55 ` Greg Kroah-Hartman
2019-05-01 6:21 ` Naresh Kamboju
2019-05-01 7:55 ` Greg Kroah-Hartman
2019-05-01 8:26 ` Jon Hunter
2019-05-01 8:43 ` Greg Kroah-Hartman
2019-05-01 16:44 ` Guenter Roeck
2019-05-01 17:14 ` Greg Kroah-Hartman
2019-05-02 5:30 ` Bharath Vedartham
2019-05-02 6:44 ` Greg Kroah-Hartman
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