- 22 Aug, 2018 40 commits
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Manfred Spraul authored
The varable names got a mess, thus standardize them again: id: user space id. Called semid, shmid, msgid if the type is known. Most functions use "id" already. idx: "index" for the idr lookup Right now, some functions use lid, ipc_addid() already uses idx as the variable name. seq: sequence number, to avoid quick collisions of the user space id key: user space key, used for the rhash tree Link: http://lkml.kernel.org/r/20180712185241.4017-12-manfred@colorfullife.comSigned-off-by:Manfred Spraul <manfred@colorfullife.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Davidlohr Bueso authored
Now that we know that rhashtable_init() will not fail, we can get rid of a lot of the unnecessary cleanup paths when the call errored out. [manfred@colorfullife.com: variable name added to util.h to resolve checkpatch warning] Link: http://lkml.kernel.org/r/20180712185241.4017-11-manfred@colorfullife.comSigned-off-by:
Davidlohr Bueso <dbueso@suse.de> Signed-off-by:
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Davidlohr Bueso authored
In sysvipc we have an ids->tables_initialized regarding the rhashtable, introduced in 0cfb6aee ("ipc: optimize semget/shmget/msgget for lots of keys") It's there, specifically, to prevent nil pointer dereferences, from using an uninitialized api. Considering how rhashtable_init() can fail (probably due to ENOMEM, if anything), this made the overall ipc initialization capable of failure as well. That alone is ugly, but fine, however I've spotted a few issues regarding the semantics of tables_initialized (however unlikely they may be): - There is inconsistency in what we return to userspace: ipc_addid() returns ENOSPC which is certainly _wrong_, while ipc_obtain_object_idr() returns EINVAL. - After we started using rhashtables, ipc_findkey() can return nil upon !tables_initialized, but the caller expects nil for when the ipc structure isn't found, and can therefore call into ipcget() callbacks. Now that rhashtable initialization cannot fail, we can properly get rid of the hack altogether. [manfred@colorfullife.com: commit id extended to 12 digits] Link: http://lkml.kernel.org/r/20180712185241.4017-10-manfred@colorfullife.comSigned-off-by:
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Davidlohr Bueso authored
rhashtable_init() may fail due to -ENOMEM, thus making the entire api unusable. This patch removes this scenario, however unlikely. In order to guarantee memory allocation, this patch always ends up doing GFP_KERNEL|__GFP_NOFAIL for both the tbl as well as alloc_bucket_spinlocks(). Upon the first table allocation failure, we shrink the size to the smallest value that makes sense and retry with __GFP_NOFAIL semantics. With the defaults, this means that from 64 buckets, we retry with only 4. Any later issues regarding performance due to collisions or larger table resizing (when more memory becomes available) is the least of our problems. Link: http://lkml.kernel.org/r/20180712185241.4017-9-manfred@colorfullife.comSigned-off-by:
Herbert Xu <herbert@gondor.apana.org.au> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by:
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Davidlohr Bueso authored
As of ce91f6ee ("mm: kvmalloc does not fallback to vmalloc for incompatible gfp flags") we can simplify the caller and trust kvzalloc() to just do the right thing. For the case of the GFP_ATOMIC context, we can drop the __GFP_NORETRY flag for obvious reasons, and for the __GFP_NOWARN case, however, it is changed such that the caller passes the flag instead of making bucket_table_alloc() handle it. This slightly changes the gfp flags passed on to nested_table_alloc() as it will now also use GFP_ATOMIC | __GFP_NOWARN. However, I consider this a positive consequence as for the same reasons we want nowarn semantics in bucket_table_alloc(). [manfred@colorfullife.com: commit id extended to 12 digits, line wraps updated] Link: http://lkml.kernel.org/r/20180712185241.4017-8-manfred@colorfullife.comSigned-off-by:
Michal Hocko <mhocko@suse.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by:
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Davidlohr Bueso authored
ipc/util.c contains multiple functions to get the ipc object pointer given an id number. There are two sets of function: One set verifies the sequence counter part of the id number, other functions do not check the sequence counter. The standard for function names in ipc/util.c is - ..._check() functions verify the sequence counter - ..._idr() functions do not verify the sequence counter ipc_lock() is an exception: It does not verify the sequence counter value, but this is not obvious from the function name. Furthermore, shm.c is the only user of this helper. Thus, we can simply move the logic into shm_lock() and get rid of the function altogether. [manfred@colorfullife.com: most of changelog] Link: http://lkml.kernel.org/r/20180712185241.4017-7-manfred@colorfullife.comSigned-off-by:
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Manfred Spraul authored
The comment that explains ipc_obtain_object_check is wrong: The function checks the sequence number, not the reference counter. Note that checking the reference counter would be meaningless: The reference counter is decreased without holding any locks, thus an object with kern_ipc_perm.deleted=true may disappear at the end of the next rcu grace period. Link: http://lkml.kernel.org/r/20180712185241.4017-6-manfred@colorfullife.comSigned-off-by:
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Manfred Spraul authored
Both the comment and the name of ipcctl_pre_down_nolock() are misleading: The function must be called while holdling the rw semaphore. Therefore the patch renames the function to ipcctl_obtain_check(): This name matches the other names used in util.c: - "obtain" function look up a pointer in the idr, without acquiring the object lock. - The caller is responsible for locking. - _check means that the sequence number is checked. Link: http://lkml.kernel.org/r/20180712185241.4017-5-manfred@colorfullife.comSigned-off-by:
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Manfred Spraul authored
ipc_addid() is impossible to use: - for certain failures, the caller must not use ipc_rcu_putref(), because the reference counter is not yet initialized. - for other failures, the caller must use ipc_rcu_putref(), because parallel operations could be ongoing already. The patch cleans that up, by initializing the refcount early, and by modifying all callers. The issues is related to the finding of syzbot+2827ef6b3385deb07eaf@syzkaller.appspotmail.com: syzbot found an issue with reading kern_ipc_perm.seq, here both read and write to already released memory could happen. Link: http://lkml.kernel.org/r/20180712185241.4017-4-manfred@colorfullife.comSigned-off-by:
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Manfred Spraul authored
ipc_addid() initializes kern_ipc_perm.seq after having called idr_alloc() (within ipc_idr_alloc()). Thus a parallel semop() or msgrcv() that uses ipc_obtain_object_check() may see an uninitialized value. The patch moves the initialization of kern_ipc_perm.seq before the calls of idr_alloc(). Notes: 1) This patch has a user space visible side effect: If /proc/sys/kernel/*_next_id is used (i.e.: checkpoint/restore) and if semget()/msgget()/shmget() fails in the final step of adding the id to the rhash tree, then .._next_id is cleared. Before the patch, is remained unmodified. There is no change of the behavior after a successful ..get() call: It always clears .._next_id, there is no impact to non checkpoint/restore code as that code does not use .._next_id. 2) The patch correctly documents that after a call to ipc_idr_alloc(), the full tear-down sequence must be used. The callers of ipc_addid() do not fullfill that, i.e. more bugfixes are required. The patch is a squash of a patch from Dmitry and my own changes. Link: http://lkml.kernel.org/r/20180712185241.4017-3-manfred@colorfullife.com Reported-by: syzbot+2827ef6b3385deb07eaf@syzkaller.appspotmail.com Signed-off-by:
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Manfred Spraul authored
ipc_addid() initializes kern_ipc_perm.id after having called ipc_idr_alloc(). Thus a parallel semctl() or msgctl() that uses e.g. MSG_STAT may use this unitialized value as the return code. The patch moves all accesses to kern_ipc_perm.id under the spin_lock(). The issues is related to the finding of syzbot+2827ef6b3385deb07eaf@syzkaller.appspotmail.com: syzbot found an issue with kern_ipc_perm.seq Link: http://lkml.kernel.org/r/20180712185241.4017-2-manfred@colorfullife.comSigned-off-by:
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Adrian Reber authored
The CHECKPOINT_RESTORE configuration option was introduced in 2012 and combined with EXPERT. CHECKPOINT_RESTORE is already enabled in many distribution kernels and also part of the defconfigs of various architectures. To make it easier for distributions to enable CHECKPOINT_RESTORE this removes EXPERT and moves the configuration option out of the EXPERT block. Link: http://lkml.kernel.org/r/20180712130733.11510-1-adrian@lisas.deSigned-off-by:
Adrian Reber <adrian@lisas.de> Acked-by:
Oleg Nesterov <oleg@redhat.com> Reviewed-by:
Hendrik Brueckner <brueckner@linux.ibm.com> Acked-by:
Pavel Emelyanov <xemul@virtuozzo.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by:
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Arnd Bergmann authored
get_seconds() is deprecated in favor of ktime_get_real_seconds(), which returns a 64-bit timestamp. In the SYSV file system, the superblock timestamp is only 32 bits wide, and it is used to check whether a file system is clean, so the best solution seems to be to force a wraparound and explicitly convert it to an unsigned 32-bit value. This is independent of the inode timestamps that are also 32-bit wide on disk and that come from current_time(). Link: http://lkml.kernel.org/r/20180713145236.3152513-1-arnd@arndb.deSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Acked-by:
Thomas Gleixner <tglx@linutronix.de> Reviewed-by:
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Arnd Bergmann authored
We just truncate the seconds to 32-bit in one place now, so this can trivially be converted over to using timespec64 consistently. Link: http://lkml.kernel.org/r/20180620100133.4035614-1-arnd@arndb.deSigned-off-by:
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Randy Dunlap authored
Fix a few typos/spellos in kernel/sysctl.c. Link: http://lkml.kernel.org/r/bb09a8b9-f984-6dd4-b07b-3ecaf200862e@infradead.orgSigned-off-by:
Randy Dunlap <rdunlap@infradead.org> Acked-by:
Kees Cook <keescook@chromium.org> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Signed-off-by:
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Colin Ian King authored
Pointer md is being assigned but is never used hence it is redundant and can be removed. Cleans up clang warning: warning: variable 'md' set but not used [-Wunused-but-set-variable] Link: http://lkml.kernel.org/r/20180711082346.5223-1-colin.king@canonical.comSigned-off-by:
Colin Ian King <colin.king@canonical.com> Acked-by:
Alexandre Bounine <alex.bou9@gmail.com> Signed-off-by:
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Jann Horn authored
Before this change, if a multithreaded process forks while one of its threads is changing a signal handler using sigaction(), the memcpy() in copy_sighand() can race with the struct assignment in do_sigaction(). It isn't clear whether this can cause corruption of the userspace signal handler pointer, but it definitely can cause inconsistency between different fields of struct sigaction. Take the appropriate spinlock to avoid this. I have tested that this patch prevents inconsistency between sa_sigaction and sa_flags, which is possible before this patch. Link: http://lkml.kernel.org/r/20180702145108.73189-1-jannh@google.comSigned-off-by:
Jann Horn <jannh@google.com> Acked-by:
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Christian Brauner authored
make get_signal() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-18-christian@brauner.ioSigned-off-by:
Christian Brauner <christian@brauner.io> Reviewed-by:
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Christian Brauner authored
sigkill_pending() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-17-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
legacy_queue() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-16-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
wants_signal() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-15-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
The return value of flush_sigqueue_mask() is never checked anywhere. Link: http://lkml.kernel.org/r/20180602103653.18181-14-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
unhandled_signal() already behaves like a boolean function. Let's actually declare it as such too. All callers treat it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-13-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
recalc_sigpending_tsk() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-12-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
has_pending_signals() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-11-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
sig_ignored() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-10-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
sig_task_ignored() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-9-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
sig_handler_ignored() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-8-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
kill_ok_by_cred() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-7-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
The goto is not needed and does not add any clarity. Simply return -EINVAL on unexpected sigset_t struct size directly. Link: http://lkml.kernel.org/r/20180602103653.18181-6-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
do_sigpending() returned 0 unconditionally so it doesn't make sense to have it return at all. This allows us to simplify a bunch of syscall callers. Link: http://lkml.kernel.org/r/20180602103653.18181-5-christian@brauner.ioSigned-off-by:
Al Viro <viro@zeniv.linux.org.uk> Acked-by:
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Christian Brauner authored
may_ptrace_stop() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-4-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
kill_as_cred_perm() already behaves like a boolean function. Let's actually declare it as such too. Link: http://lkml.kernel.org/r/20180602103653.18181-3-christian@brauner.ioSigned-off-by:
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Christian Brauner authored
Patch series "signal: refactor some functions", v3. This series refactors a bunch of functions in signal.c to simplify parts of the code. The greatest single change is declaring the static do_sigpending() helper as void which makes it possible to remove a bunch of unnecessary checks in the syscalls later on. This patch (of 17): force_sigsegv() returned 0 unconditionally so it doesn't make sense to have it return at all. In addition, there are no callers that check force_sigsegv()'s return value. Link: http://lkml.kernel.org/r/20180602103653.18181-2-christian@brauner.ioSigned-off-by:
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Arnd Bergmann authored
Now that we pass down 64-bit timestamps from VFS, we just need to convert that correctly into on-disk timestamps. To make that work correctly, this changes the last use of time_to_tm() in the kernel to time64_to_tm(), which also lets use remove that deprecated interfaces. Similarly, the time_t use in fat_time_fat2unix() truncates the timestamp on the way in, which can be avoided by using types that are wide enough to hold the intermediate values during the conversion. [hirofumi@mail.parknet.co.jp: remove useless temporary variable, needless long long] Link: http://lkml.kernel.org/r/20180619153646.3637529-1-arnd@arndb.deSigned-off-by:
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Jeff Layton <jlayton@redhat.com> Signed-off-by:
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OGAWA Hirofumi authored
On corrupted FATfs may have invalid ->i_start. To handle it, this checks ->i_start before using, and return proper error code. Link: http://lkml.kernel.org/r/87o9f8y1t5.fsf_-_@mail.parknet.co.jpSigned-off-by:
Anatoly Trosinenko <anatoly.trosinenko@gmail.com> Tested-by:
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Wentao Wang authored
Add FITRIM ioctl for FAT file system [witallwang@gmail.com: use u64s] Link: http://lkml.kernel.org/r/87h8l37hub.fsf@mail.parknet.co.jp [hirofumi@mail.parknet.co.jp: bug fixes, coding style fixes, add signal check] Link: http://lkml.kernel.org/r/87fu10anhj.fsf@mail.parknet.co.jpSigned-off-by:
Wentao Wang <witallwang@gmail.com> Signed-off-by:
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Jann Horn authored
This fixes the following issues: - When a buffer size is supplied to reiserfs_listxattr() such that each individual name fits, but the concatenation of all names doesn't fit, reiserfs_listxattr() overflows the supplied buffer. This leads to a kernel heap overflow (verified using KASAN) followed by an out-of-bounds usercopy and is therefore a security bug. - When a buffer size is supplied to reiserfs_listxattr() such that a name doesn't fit, -ERANGE should be returned. But reiserfs instead just truncates the list of names; I have verified that if the only xattr on a file has a longer name than the supplied buffer length, listxattr() incorrectly returns zero. With my patch applied, -ERANGE is returned in both cases and the memory corruption doesn't happen anymore. Credit for making me clean this code up a bit goes to Al Viro, who pointed out that the ->actor calling convention is suboptimal and should be changed. Link: http://lkml.kernel.org/r/20180802151539.5373-1-jannh@google.com Fixes: 48b32a35 ("reiserfs: use generic xattr handlers") Signed-off-by:
Jeff Mahoney <jeffm@suse.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by:
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Arnd Bergmann authored
This uses the deprecated time_t type but is write-only, and could be removed, but as Jeff explains, having a timestamp can be usefule for post-mortem analysis in crash dumps. In order to remove one of the last instances of time_t, this changes the type to time64_t, same as j_trans_start_time. Link: http://lkml.kernel.org/r/20180622133315.221210-1-arnd@arndb.deSigned-off-by:
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Arnd Bergmann authored
Before linux-2.4.6, print_time() was used to pretty-print an inode time when running reiserfs in user space, after that it has become obsolete and is still a bit incorrect: It behaves differently on 32-bit and 64-bit machines, and uses a static buffer to hold a string, which could lead to undefined behavior if we ever called this from multiple places simultaneously. Since we always want to treat the timestamps as 'unsigned' anyway, simply printing them as an integer is both simpler and safer while avoiding the deprecated time_t type. Link: http://lkml.kernel.org/r/20180620142522.27639-3-arnd@arndb.deSigned-off-by:
Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by:
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