Merge tag 'v6.11' into for-6.12/block

Merge in 6.11 final to get the fix for preventing deadlocks on an
elevator switch, as there's a fixup for that patch.

* tag 'v6.11': (1788 commits)
  Linux 6.11
  Revert "KVM: VMX: Always honor guest PAT on CPUs that support self-snoop"
  pinctrl: pinctrl-cy8c95x0: Fix regcache
  cifs: Fix signature miscalculation
  mm: avoid leaving partial pfn mappings around in error case
  drm/xe/client: add missing bo locking in show_meminfo()
  drm/xe/client: fix deadlock in show_meminfo()
  drm/xe/oa: Enable Xe2+ PES disaggregation
  drm/xe/display: fix compat IS_DISPLAY_STEP() range end
  drm/xe: Fix access_ok check in user_fence_create
  drm/xe: Fix possible UAF in guc_exec_queue_process_msg
  drm/xe: Remove fence check from send_tlb_invalidation
  drm/xe/gt: Remove double include
  net: netfilter: move nf flowtable bpf initialization in nf_flow_table_module_init()
  PCI: Fix potential deadlock in pcim_intx()
  workqueue: Clear worker->pool in the worker thread context
  net: tighten bad gso csum offset check in virtio_net_hdr
  netlink: specs: mptcp: fix port endianness
  net: dpaa: Pad packets to ETH_ZLEN
  mptcp: pm: Fix uaf in __timer_delete_sync
  ...

1 files changed, 14 insertions, 17 deletions

diff --git a/fs/file.c b/fs/file.c
index a3b72aa64f11..655338effe9c 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -46,27 +46,23 @@ static void free_fdtable_rcu(struct rcu_head *rcu)
 #define BITBIT_NR(nr)	BITS_TO_LONGS(BITS_TO_LONGS(nr))
 #define BITBIT_SIZE(nr)	(BITBIT_NR(nr) * sizeof(long))
 
+#define fdt_words(fdt) ((fdt)->max_fds / BITS_PER_LONG) // words in ->open_fds
 /*
  * Copy 'count' fd bits from the old table to the new table and clear the extra
  * space if any.  This does not copy the file pointers.  Called with the files
  * spinlock held for write.
  */
-static void copy_fd_bitmaps(struct fdtable *nfdt, struct fdtable *ofdt,
-			    unsigned int count)
+static inline void copy_fd_bitmaps(struct fdtable *nfdt, struct fdtable *ofdt,
+			    unsigned int copy_words)
 {
-	unsigned int cpy, set;
-
-	cpy = count / BITS_PER_BYTE;
-	set = (nfdt->max_fds - count) / BITS_PER_BYTE;
-	memcpy(nfdt->open_fds, ofdt->open_fds, cpy);
-	memset((char *)nfdt->open_fds + cpy, 0, set);
-	memcpy(nfdt->close_on_exec, ofdt->close_on_exec, cpy);
-	memset((char *)nfdt->close_on_exec + cpy, 0, set);
-
-	cpy = BITBIT_SIZE(count);
-	set = BITBIT_SIZE(nfdt->max_fds) - cpy;
-	memcpy(nfdt->full_fds_bits, ofdt->full_fds_bits, cpy);
-	memset((char *)nfdt->full_fds_bits + cpy, 0, set);
+	unsigned int nwords = fdt_words(nfdt);
+
+	bitmap_copy_and_extend(nfdt->open_fds, ofdt->open_fds,
+			copy_words * BITS_PER_LONG, nwords * BITS_PER_LONG);
+	bitmap_copy_and_extend(nfdt->close_on_exec, ofdt->close_on_exec,
+			copy_words * BITS_PER_LONG, nwords * BITS_PER_LONG);
+	bitmap_copy_and_extend(nfdt->full_fds_bits, ofdt->full_fds_bits,
+			copy_words, nwords);
 }
 
 /*
@@ -84,7 +80,7 @@ static void copy_fdtable(struct fdtable *nfdt, struct fdtable *ofdt)
 	memcpy(nfdt->fd, ofdt->fd, cpy);
 	memset((char *)nfdt->fd + cpy, 0, set);
 
-	copy_fd_bitmaps(nfdt, ofdt, ofdt->max_fds);
+	copy_fd_bitmaps(nfdt, ofdt, fdt_words(ofdt));
 }
 
 /*
@@ -379,7 +375,7 @@ struct files_struct *dup_fd(struct files_struct *oldf, unsigned int max_fds, int
 		open_files = sane_fdtable_size(old_fdt, max_fds);
 	}
 
-	copy_fd_bitmaps(new_fdt, old_fdt, open_files);
+	copy_fd_bitmaps(new_fdt, old_fdt, open_files / BITS_PER_LONG);
 
 	old_fds = old_fdt->fd;
 	new_fds = new_fdt->fd;
@@ -1248,6 +1244,7 @@ __releases(&files->file_lock)
 	 * tables and this condition does not arise without those.
 	 */
 	fdt = files_fdtable(files);
+	fd = array_index_nospec(fd, fdt->max_fds);
 	tofree = fdt->fd[fd];
 	if (!tofree && fd_is_open(fd, fdt))
 		goto Ebusy;