5.4-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Marzinski bmarzins@redhat.com
commit 5a2a6c428190f945c5cbf5791f72dbea83e97f66 upstream.
realloc_argv() was only updating the array size if it was called with old_argv already allocated. The first time it was called to create an argv array, it would allocate the array but return the array size as zero. dm_split_args() would think that it couldn't store any arguments in the array and would call realloc_argv() again, causing it to reallocate the initial slots (this time using GPF_KERNEL) and finally return a size. Aside from being wasteful, this could cause deadlocks on targets that need to process messages without starting new IO. Instead, realloc_argv should always update the allocated array size on success.
Fixes: a0651926553c ("dm table: don't copy from a NULL pointer in realloc_argv()") Cc: stable@vger.kernel.org Signed-off-by: Benjamin Marzinski bmarzins@redhat.com Signed-off-by: Mikulas Patocka mpatocka@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/dm-table.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -573,9 +573,10 @@ static char **realloc_argv(unsigned *siz gfp = GFP_NOIO; } argv = kmalloc_array(new_size, sizeof(*argv), gfp); - if (argv && old_argv) { - memcpy(argv, old_argv, *size * sizeof(*argv)); + if (argv) { *size = new_size; + if (old_argv) + memcpy(argv, old_argv, *size * sizeof(*argv)); }
kfree(old_argv);