Eric Lee / linux-smarc-t335x-v3.2

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Commit 9438fabb73eb48055b58b89fc51e0bc4db22fabd

Authored by Jeff Layton
Committed by Steve French
1 parent 9d037a7776
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

cifs: fix possible memory corruption in CIFSFindNext 

The name_len variable in CIFSFindNext is a signed int that gets set to
the resume_name_len in the cifs_search_info. The resume_name_len however
is unsigned and for some infolevels is populated directly from a 32 bit
value sent by the server.

If the server sends a very large value for this, then that value could
look negative when converted to a signed int. That would make that
value pass the PATH_MAX check later in CIFSFindNext. The name_len would
then be used as a length value for a memcpy. It would then be treated
as unsigned again, and the memcpy scribbles over a ton of memory.

Fix this by making the name_len an unsigned value in CIFSFindNext.

Cc: <stable@kernel.org>
Reported-by: Darren Lavender <dcl@hppine99.gbr.hp.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

Showing 1 changed file with 2 additions and 1 deletions Side-by-side Diff

... ... @@ -4079,7 +4079,8 @@
4079 4079 T2_FNEXT_RSP_PARMS *parms;
4080 4080 char *response_data;
4081 4081 int rc = 0;
4082   - int bytes_returned, name_len;
  4082 + int bytes_returned;
  4083 + unsigned int name_len;
4083 4084 __u16 params, byte_count;
4084 4085  
4085 4086 cFYI(1, "In FindNext");