When an application called fsync on a file in Coda a small request with
just the file identifier was allocated, but the declared length was set
to the size of union of all possible upcall requests.
This bug has been around for a very long time and is now caught by the
extra checking in usercopy that was introduced in Linux-4.8.
The exposure happens when the Coda cache manager process reads the fsync
upcall request at which point it is killed. As a result there is nobody
servicing any further upcalls, trapping any processes that try to access
the mounted Coda filesystem.
Signed-off-by: Jan Harkes <email address hidden>
Signed-off-by: Al Viro <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
For systems with X86_FEATURE_TOPOEXT, current logic uses the APIC ID
to calculate shared_cpu_map. However, APIC IDs are not guaranteed to
be contiguous for cores across different L3s (e.g. family17h system
w/ downcore configuration). This breaks the logic, and results in an
incorrect L3 shared_cpu_map.
Instead, always use the previously calculated cpu_llc_shared_mask of
each CPU to derive the L3 shared_cpu_map.
online_page_ext() and page_ext_init() allocate page_ext for each
section, but they do not allocate if the first PFN is !pfn_present(pfn)
or !pfn_valid(pfn). Then section->page_ext remains as NULL.
lookup_page_ext checks NULL only if CONFIG_DEBUG_VM is enabled. For a
valid PFN, __set_page_owner will try to get page_ext through
lookup_page_ext. Without CONFIG_DEBUG_VM lookup_page_ext will misuse
NULL pointer as value 0. This incurrs invalid address access.
This is the panic example when PFN 0x100000 is not valid but PFN
0x13FC00 is being used for page_ext. section->page_ext is NULL,
get_entry returned invalid page_ext address as 0x1DFA000 for a PFN
0x13FC00.
To avoid this panic, CONFIG_DEBUG_VM should be removed so that page_ext
will be checked at all times.
Unable to handle kernel paging request at virtual address 01dfa014
------------[ cut here ]------------
Kernel BUG at ffffff80082371e0 [verbose debug info unavailable]
Internal error: Oops: 96000045 [#1] PREEMPT SMP
Modules linked in:
PC is at __set_page_owner+0x48/0x78
LR is at __set_page_owner+0x44/0x78
__set_page_owner+0x48/0x78
get_page_from_freelist+0x880/0x8e8
__alloc_pages_nodemask+0x14c/0xc48
__do_page_cache_readahead+0xdc/0x264
filemap_fault+0x2ac/0x550
ext4_filemap_fault+0x3c/0x58
__do_fault+0x80/0x120
handle_mm_fault+0x704/0xbb0
do_page_fault+0x2e8/0x394
do_mem_abort+0x88/0x124
Pre-4.7 kernels also need commit f86e4271978b ("mm: check the return
value of lookup_page_ext for all call sites").
In reset_deferred_meminit() we determine number of pages that must not
be deferred. We initialize pages for at least 2G of memory, but also
pages for reserved memory in this node.
The reserved memory is determined in this function:
memblock_reserved_memory_within(), which operates over physical
addresses, and returns size in bytes. However, reset_deferred_meminit()
assumes that that this function operates with pfns, and returns page
count.
The result is that in the best case machine boots slower than expected
due to initializing more pages than needed in single thread, and in the
worst case panics because fewer than needed pages are initialized early.
When I set the timeout to a specific value such as 500ms, the timeout
event will not happen in time due to the overflow in function
check_msg_timeout:
...
ent->timeout -= timeout_period;
if (ent->timeout > 0)
return;
...
The type of timeout_period is long, but ent->timeout is unsigned long.
This patch makes the type consistent.
we should wait dio requests to finish before inode lock in
ocfs2_setattr(), otherwise the following deadlock will happen:
process 1 process 2 process 3
truncate file 'A' end_io of writing file 'A' receiving the bast messages
ocfs2_setattr
ocfs2_inode_lock_tracker
ocfs2_inode_lock_full
inode_dio_wait
__inode_dio_wait
-->waiting for all dio
requests finish dlm_proxy_ast_handler dlm_do_local_bast ocfs2_blocking_ast ocfs2_generic_handle_bast set OCFS2_LOCK_BLOCKED flag dio_end_io dio_bio_end_aio dio_complete ocfs2_dio_end_io ocfs2_dio_end_io_write ocfs2_inode_lock __ocfs2_cluster_lock ocfs2_wait_for_mask -->waiting for OCFS2_LOCK_BLOCKED flag to be cleared, that is waiting for 'process 1' unlocking the inode lock inode_dio_end -->here dec the i_dio_count, but will never be called, so a deadlock happened.
Link: http://<email address hidden>
Signed-off-by: Alex Chen <email address hidden>
Reviewed-by: Jun Piao <email address hidden>
Reviewed-by: Joseph Qi <email address hidden>
Acked-by: Changwei Ge <email address hidden>
Cc: Mark Fasheh <email address hidden>
Cc: Joel Becker <email address hidden>
Cc: Junxiao Bi <email address hidden>
Signed-off-by: Andrew Morton <email address hidden>
Signed-off-by: Linus Torvalds <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
When a node dies, other live nodes have to choose a new master for an
existed lock resource mastered by the dead node.
As for ocfs2/dlm implementation, this is done by function -
dlm_move_lockres_to_recovery_list which marks those lock rsources as
DLM_LOCK_RES_RECOVERING and manages them via a list from which DLM
changes lock resource's master later.
So without invoking dlm_move_lockres_to_recovery_list, no master will be
choosed after dlm recovery accomplishment since no lock resource can be
found through ::resource list.
What's worse is that if DLM_LOCK_RES_RECOVERING is not marked for lock
resources mastered a dead node, it will break up synchronization among
nodes.
So invoke dlm_move_lockres_to_recovery_list again.
Fixs: 'commit ee8f7fcbe638 ("ocfs2/dlm: continue to purge recovery lockres when recovery master goes down")'
Link: http://<email address hidden>
Signed-off-by: Changwei Ge <email address hidden>
Reported-by: Vitaly Mayatskih <email address hidden>
Tested-by: Vitaly Mayatskikh <email address hidden>
Cc: Mark Fasheh <email address hidden>
Cc: Joel Becker <email address hidden>
Cc: Junxiao Bi <email address hidden>
Cc: Joseph Qi <email address hidden>
Signed-off-by: Andrew Morton <email address hidden>
Signed-off-by: Linus Torvalds <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
This matters at least for the mincore syscall, which will otherwise copy
uninitialized memory from the page allocator to userspace. It is
probably also a correctness error for /proc/$pid/pagemap, but I haven't
tested that.
Removing the `walk->hugetlb_entry` condition in walk_hugetlb_range() has
no effect because the caller already checks for that.
This only reports holes in hugetlb ranges to callers who have specified
a hugetlb_entry callback.
This issue was found using an AFL-based fuzzer.
v2:
- don't crash on ->pte_hole==NULL (Andrew Morton)
- add Cc stable (Andrew Morton)
The pending-callbacks check in rcu_prepare_for_idle() is backwards.
It should accelerate if there are pending callbacks, but the check
rather uselessly accelerates only if there are no callbacks. This commit
therefore inverts this check.
Fixes: 15fecf89e46a ("srcu: Abstract multi-tail callback list handling")
Signed-off-by: Neeraj Upadhyay <email address hidden>
Signed-off-by: Paul E. McKenney <email address hidden>
Signed-off-by: Greg Kroah-Hartman <email address hidden>
