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-rw-r--r--fs/file.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/fs/file.c b/fs/file.c
index b6db031545e6..6d2275c3be9c 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -197,6 +197,21 @@ static struct fdtable *alloc_fdtable(unsigned int slots_wanted)
return ERR_PTR(-EMFILE);
}
+ /*
+ * Check if the allocation size would exceed INT_MAX. kvmalloc_array()
+ * and kvmalloc() will warn if the allocation size is greater than
+ * INT_MAX, as filp_cachep objects are not __GFP_NOWARN.
+ *
+ * This can happen when sysctl_nr_open is set to a very high value and
+ * a process tries to use a file descriptor near that limit. For example,
+ * if sysctl_nr_open is set to 1073741816 (0x3ffffff8) - which is what
+ * systemd typically sets it to - then trying to use a file descriptor
+ * close to that value will require allocating a file descriptor table
+ * that exceeds 8GB in size.
+ */
+ if (unlikely(nr > INT_MAX / sizeof(struct file *)))
+ return ERR_PTR(-EMFILE);
+
fdt = kmalloc(sizeof(struct fdtable), GFP_KERNEL_ACCOUNT);
if (!fdt)
goto out;