1. 01 Jan, 2024 11 commits
  2. 30 Dec, 2023 5 commits
    • Linus Torvalds's avatar
      Merge tag 'trace-v6.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace · 453f5db0
      Linus Torvalds authored
      Pull tracing fixes from Steven Rostedt:
      
       - Fix readers that are blocked on the ring buffer when buffer_percent
         is 100%. They are supposed to wake up when the buffer is full, but
         because the sub-buffer that the writer is on is never considered
         "dirty" in the calculation, dirty pages will never equal nr_pages.
         Add +1 to the dirty count in order to count for the sub-buffer that
         the writer is on.
      
       - When a reader is blocked on the "snapshot_raw" file, it is to be
         woken up when a snapshot is done and be able to read the snapshot
         buffer. But because the snapshot swaps the buffers (the main one with
         the snapshot one), and the snapshot reader is waiting on the old
         snapshot buffer, it was not woken up (because it is now on the main
         buffer after the swap). Worse yet, when it reads the buffer after a
         snapshot, it's not reading the snapshot buffer, it's reading the live
         active main buffer.
      
         Fix this by forcing a wakeup of all readers on the snapshot buffer
         when a new snapshot happens, and then update the buffer that the
         reader is reading to be back on the snapshot buffer.
      
       - Fix the modification of the direct_function hash. There was a race
         when new functions were added to the direct_function hash as when it
         moved function entries from the old hash to the new one, a direct
         function trace could be hit and not see its entry.
      
         This is fixed by allocating the new hash, copy all the old entries
         onto it as well as the new entries, and then use rcu_assign_pointer()
         to update the new direct_function hash with it.
      
         This also fixes a memory leak in that code.
      
       - Fix eventfs ownership
      
      * tag 'trace-v6.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
        ftrace: Fix modification of direct_function hash while in use
        tracing: Fix blocked reader of snapshot buffer
        ring-buffer: Fix wake ups when buffer_percent is set to 100
        eventfs: Fix file and directory uid and gid ownership
      453f5db0
    • David Laight's avatar
      locking/osq_lock: Clarify osq_wait_next() · b106bcf0
      David Laight authored
      Directly return NULL or 'next' instead of breaking out of the loop.
      Signed-off-by: default avatarDavid Laight <david.laight@aculab.com>
      [ Split original patch into two independent parts  - Linus ]
      Link: https://lore.kernel.org/lkml/7c8828aec72e42eeb841ca0ee3397e9a@AcuMS.aculab.com/Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b106bcf0
    • David Laight's avatar
      locking/osq_lock: Clarify osq_wait_next() calling convention · 563adbfc
      David Laight authored
      osq_wait_next() is passed 'prev' from osq_lock() and NULL from
      osq_unlock() but only needs the 'cpu' value to write to lock->tail.
      
      Just pass prev->cpu or OSQ_UNLOCKED_VAL instead.
      
      Should have no effect on the generated code since gcc manages to assume
      that 'prev != NULL' due to an earlier dereference.
      Signed-off-by: default avatarDavid Laight <david.laight@aculab.com>
      [ Changed 'old' to 'old_cpu' by request from Waiman Long  - Linus ]
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      563adbfc
    • David Laight's avatar
      locking/osq_lock: Move the definition of optimistic_spin_node into osq_lock.c · 7c223098
      David Laight authored
      struct optimistic_spin_node is private to the implementation.
      Move it into the C file to ensure nothing is accessing it.
      Signed-off-by: default avatarDavid Laight <david.laight@aculab.com>
      Acked-by: default avatarWaiman Long <longman@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7c223098
    • Steven Rostedt (Google)'s avatar
      ftrace: Fix modification of direct_function hash while in use · d05cb470
      Steven Rostedt (Google) authored
      Masami Hiramatsu reported a memory leak in register_ftrace_direct() where
      if the number of new entries are added is large enough to cause two
      allocations in the loop:
      
              for (i = 0; i < size; i++) {
                      hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
                              new = ftrace_add_rec_direct(entry->ip, addr, &free_hash);
                              if (!new)
                                      goto out_remove;
                              entry->direct = addr;
                      }
              }
      
      Where ftrace_add_rec_direct() has:
      
              if (ftrace_hash_empty(direct_functions) ||
                  direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
                      struct ftrace_hash *new_hash;
                      int size = ftrace_hash_empty(direct_functions) ? 0 :
                              direct_functions->count + 1;
      
                      if (size < 32)
                              size = 32;
      
                      new_hash = dup_hash(direct_functions, size);
                      if (!new_hash)
                              return NULL;
      
                      *free_hash = direct_functions;
                      direct_functions = new_hash;
              }
      
      The "*free_hash = direct_functions;" can happen twice, losing the previous
      allocation of direct_functions.
      
      But this also exposed a more serious bug.
      
      The modification of direct_functions above is not safe. As
      direct_functions can be referenced at any time to find what direct caller
      it should call, the time between:
      
                      new_hash = dup_hash(direct_functions, size);
       and
                      direct_functions = new_hash;
      
      can have a race with another CPU (or even this one if it gets interrupted),
      and the entries being moved to the new hash are not referenced.
      
      That's because the "dup_hash()" is really misnamed and is really a
      "move_hash()". It moves the entries from the old hash to the new one.
      
      Now even if that was changed, this code is not proper as direct_functions
      should not be updated until the end. That is the best way to handle
      function reference changes, and is the way other parts of ftrace handles
      this.
      
      The following is done:
      
       1. Change add_hash_entry() to return the entry it created and inserted
          into the hash, and not just return success or not.
      
       2. Replace ftrace_add_rec_direct() with add_hash_entry(), and remove
          the former.
      
       3. Allocate a "new_hash" at the start that is made for holding both the
          new hash entries as well as the existing entries in direct_functions.
      
       4. Copy (not move) the direct_function entries over to the new_hash.
      
       5. Copy the entries of the added hash to the new_hash.
      
       6. If everything succeeds, then use rcu_pointer_assign() to update the
          direct_functions with the new_hash.
      
      This simplifies the code and fixes both the memory leak as well as the
      race condition mentioned above.
      
      Link: https://lore.kernel.org/all/170368070504.42064.8960569647118388081.stgit@devnote2/
      Link: https://lore.kernel.org/linux-trace-kernel/20231229115134.08dd5174@gandalf.local.home
      
      Cc: stable@vger.kernel.org
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Alexei Starovoitov <ast@kernel.org>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Acked-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
      Fixes: 763e34e7 ("ftrace: Add register_ftrace_direct()")
      Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
      d05cb470
  3. 29 Dec, 2023 10 commits
  4. 28 Dec, 2023 5 commits
  5. 27 Dec, 2023 4 commits
  6. 26 Dec, 2023 2 commits
    • Edward Adam Davis's avatar
      keys, dns: Fix missing size check of V1 server-list header · 1997b3cb
      Edward Adam Davis authored
      The dns_resolver_preparse() function has a check on the size of the
      payload for the basic header of the binary-style payload, but is missing
      a check for the size of the V1 server-list payload header after
      determining that's what we've been given.
      
      Fix this by getting rid of the the pointer to the basic header and just
      assuming that we have a V1 server-list payload and moving the V1 server
      list pointer inside the if-statement.  Dealing with other types and
      versions can be left for when such have been defined.
      
      This can be tested by doing the following with KASAN enabled:
      
          echo -n -e '\x0\x0\x1\x2' | keyctl padd dns_resolver foo @p
      
      and produces an oops like the following:
      
          BUG: KASAN: slab-out-of-bounds in dns_resolver_preparse+0xc9f/0xd60 net/dns_resolver/dns_key.c:127
          Read of size 1 at addr ffff888028894084 by task syz-executor265/5069
          ...
          Call Trace:
            dns_resolver_preparse+0xc9f/0xd60 net/dns_resolver/dns_key.c:127
            __key_create_or_update+0x453/0xdf0 security/keys/key.c:842
            key_create_or_update+0x42/0x50 security/keys/key.c:1007
            __do_sys_add_key+0x29c/0x450 security/keys/keyctl.c:134
            do_syscall_x64 arch/x86/entry/common.c:52 [inline]
            do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
            entry_SYSCALL_64_after_hwframe+0x62/0x6a
      
      This patch was originally by Edward Adam Davis, but was modified by
      Linus.
      
      Fixes: b946001d3bb1 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")
      Reported-and-tested-by: syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com
      Link: https://lore.kernel.org/r/0000000000009b39bc060c73e209@google.com/Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarEdward Adam Davis <eadavis@qq.com>
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Tested-by: default avatarDavid Howells <dhowells@redhat.com>
      Cc: Edward Adam Davis <eadavis@qq.com>
      Cc: Jarkko Sakkinen <jarkko@kernel.org>
      Cc: Jeffrey E Altman <jaltman@auristor.com>
      Cc: Wang Lei <wang840925@gmail.com>
      Cc: Jeff Layton <jlayton@redhat.com>
      Cc: Steve French <sfrench@us.ibm.com>
      Cc: Marc Dionne <marc.dionne@auristor.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Jakub Kicinski <kuba@kernel.org>
      Cc: Paolo Abeni <pabeni@redhat.com>
      Reviewed-by: default avatarSimon Horman <horms@kernel.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1997b3cb
    • Christoph Hellwig's avatar
      block: renumber QUEUE_FLAG_HW_WC · 02d374f3
      Christoph Hellwig authored
      For the QUEUE_FLAG_HW_WC to actually work, it needs to have a separate
      number from QUEUE_FLAG_FUA, doh.
      
      Fixes: 43c9835b ("block: don't allow enabling a cache on devices that don't support it")
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Link: https://lore.kernel.org/r/20231226081524.180289-1-hch@lst.deSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      02d374f3
  7. 25 Dec, 2023 1 commit
  8. 24 Dec, 2023 2 commits