From 610c3618669fd609d4ed2c199d64b26f1e41549a Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 24 Mar 2017 14:13:05 +0300 Subject: mm: Fix false-positive VM_BUG_ON() in page_cache_{get,add}_speculative() [ Upstream commit 591a3d7c09fa08baff48ad86c2347dbd28a52753 ] 0day testing by Fengguang Wu triggered this crash while running Trinity: kernel BUG at include/linux/pagemap.h:151! ... CPU: 0 PID: 458 Comm: trinity-c0 Not tainted 4.11.0-rc2-00251-g2947ba0 #1 ... Call Trace: __get_user_pages_fast() get_user_pages_fast() get_futex_key() futex_requeue() do_futex() SyS_futex() do_syscall_64() entry_SYSCALL64_slow_path() It' VM_BUG_ON() due to false-negative in_atomic(). We call page_cache_get_speculative() with disabled local interrupts. It should be atomic enough. So let's check for disabled interrupts in the VM_BUG_ON() condition too, to resolve this. ( This got triggered by the conversion of the x86 GUP code to the generic GUP code. ) Reported-by: Fengguang Wu Signed-off-by: Kirill A. Shutemov Cc: Andrew Morton Cc: Aneesh Kumar K.V Cc: Kirill A. Shutemov Cc: LKP Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20170324114709.pcytvyb3d6ajux33@black.fi.intel.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- include/linux/pagemap.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index fbfadba81c5a..771774e13f10 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -153,7 +153,7 @@ static inline int page_cache_get_speculative(struct page *page) #ifdef CONFIG_TINY_RCU # ifdef CONFIG_PREEMPT_COUNT - VM_BUG_ON(!in_atomic()); + VM_BUG_ON(!in_atomic() && !irqs_disabled()); # endif /* * Preempt must be disabled here - we rely on rcu_read_lock doing @@ -191,7 +191,7 @@ static inline int page_cache_add_speculative(struct page *page, int count) #if !defined(CONFIG_SMP) && defined(CONFIG_TREE_RCU) # ifdef CONFIG_PREEMPT_COUNT - VM_BUG_ON(!in_atomic()); + VM_BUG_ON(!in_atomic() && !irqs_disabled()); # endif VM_BUG_ON_PAGE(page_count(page) == 0, page); atomic_add(count, &page->_count); -- cgit v1.2.3 From 23e4e7b49c65500cf4a4e494ee62076b009d29e6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Vincent=20Stehl=C3=A9?= Date: Sun, 9 Apr 2017 22:05:05 +0200 Subject: regulator: isl9305: fix array size MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 0c08aaf873174c95e674cf21ffcd041c589d2e5b ] ISL9305_MAX_REGULATOR is the last index used to access the init_data[] array, so we need to add one to this last index to obtain the necessary array size. This fixes the following smatch error: drivers/regulator/isl9305.c:160 isl9305_i2c_probe() error: buffer overflow 'pdata->init_data' 3 <= 3 Fixes: dec38b5ce6a9edb4 ("regulator: isl9305: Add Intersil ISL9305/H driver") Signed-off-by: Vincent Stehlé Cc: Mark Brown Signed-off-by: Mark Brown Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- include/linux/platform_data/isl9305.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/platform_data/isl9305.h b/include/linux/platform_data/isl9305.h index 1419133fa69e..4ac1a070af0a 100644 --- a/include/linux/platform_data/isl9305.h +++ b/include/linux/platform_data/isl9305.h @@ -24,7 +24,7 @@ struct regulator_init_data; struct isl9305_pdata { - struct regulator_init_data *init_data[ISL9305_MAX_REGULATOR]; + struct regulator_init_data *init_data[ISL9305_MAX_REGULATOR + 1]; }; #endif -- cgit v1.2.3 From c8c71406b74f81114b391b28395f3f3a7affdd56 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 14 Mar 2018 18:20:29 -0500 Subject: fs: Teach path_connected to handle nfs filesystems with multiple roots. commit 95dd77580ccd66a0da96e6d4696945b8cea39431 upstream. On nfsv2 and nfsv3 the nfs server can export subsets of the same filesystem and report the same filesystem identifier, so that the nfs client can know they are the same filesystem. The subsets can be from disjoint directory trees. The nfsv2 and nfsv3 filesystems provides no way to find the common root of all directory trees exported form the server with the same filesystem identifier. The practical result is that in struct super s_root for nfs s_root is not necessarily the root of the filesystem. The nfs mount code sets s_root to the root of the first subset of the nfs filesystem that the kernel mounts. This effects the dcache invalidation code in generic_shutdown_super currently called shrunk_dcache_for_umount and that code for years has gone through an additional list of dentries that might be dentry trees that need to be freed to accomodate nfs. When I wrote path_connected I did not realize nfs was so special, and it's hueristic for avoiding calling is_subdir can fail. The practical case where this fails is when there is a move of a directory from the subtree exposed by one nfs mount to the subtree exposed by another nfs mount. This move can happen either locally or remotely. With the remote case requiring that the move directory be cached before the move and that after the move someone walks the path to where the move directory now exists and in so doing causes the already cached directory to be moved in the dcache through the magic of d_splice_alias. If someone whose working directory is in the move directory or a subdirectory and now starts calling .. from the initial mount of nfs (where s_root == mnt_root), then path_connected as a heuristic will not bother with the is_subdir check. As s_root really is not the root of the nfs filesystem this heuristic is wrong, and the path may actually not be connected and path_connected can fail. The is_subdir function might be cheap enough that we can call it unconditionally. Verifying that will take some benchmarking and the result may not be the same on all kernels this fix needs to be backported to. So I am avoiding that for now. Filesystems with snapshots such as nilfs and btrfs do something similar. But as the directory tree of the snapshots are disjoint from one another and from the main directory tree rename won't move things between them and this problem will not occur. Cc: stable@vger.kernel.org Reported-by: Al Viro Fixes: 397d425dc26d ("vfs: Test for and handle paths that are unreachable from their mnt_root") Signed-off-by: "Eric W. Biederman" Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- include/linux/fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index f746a59fcc88..da79e9d66e5b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1295,6 +1295,7 @@ struct mm_struct; /* sb->s_iflags */ #define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */ #define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */ +#define SB_I_MULTIROOT 0x00000008 /* Multiple roots to the dentry tree */ /* Possible states of 'frozen' field */ enum { -- cgit v1.2.3