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authorAndrzej Zaborowski <andrew.zaborowski@intel.com>2014-06-09 16:50:40 +0200
committerMatt Fleming <matt.fleming@intel.com>2014-06-27 07:30:32 +0100
commit783ee43118dc773bc8b0342c5b230e017d5a04d0 (patch)
parent6fb8cc82c096fd5ccf277678639193cae07125a0 (diff)
efi-pstore: Fix an overflow on 32-bit builds
In generic_id the long int timestamp is multiplied by 100000 and needs an explicit cast to u64. Without that the id in the resulting pstore filename is wrong and userspace may have problems parsing it, but more importantly files in pstore can never be deleted and may fill the EFI flash (brick device?). This happens because when generic pstore code wants to delete a file, it passes the id to the EFI backend which reinterpretes it and a wrong variable name is attempted to be deleted. There's no error message but after remounting pstore, deleted files would reappear. Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 4b9dc836dcf9..e992abc5ef26 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -40,7 +40,7 @@ struct pstore_read_data {
static inline u64 generic_id(unsigned long timestamp,
unsigned int part, int count)
- return (timestamp * 100 + part) * 1000 + count;
+ return ((u64) timestamp * 100 + part) * 1000 + count;
static int efi_pstore_read_func(struct efivar_entry *entry, void *data)