From: Kees Cook <keescook@chromium.org> stable inclusion from stable-5.10 category: feature commit:93ee4b7d9f0632690713aee604c49e298e634094 issue: #I4919J -------------------------------- Since the header is a fixed small maximum size, just use a stack variable to avoid memory allocation in the write path. Signed-off-by: Kees Cook <keescook@chromium.org> (cherry picked from commit 93ee4b7d9f0632690713aee604c49e298e634094) Signed-off-by: roger <kongzhengrong@huawei.com> --- fs/pstore/ram.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 5d938d68b2b1..52bf9ba9a139 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -347,19 +347,15 @@ static ssize_t ramoops_pstore_read(struct pstore_record *record) static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz, struct pstore_record *record) { - char *hdr; + char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */ size_t len; - hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n", + len = scnprintf(hdr, sizeof(hdr), + RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n", (time64_t)record->time.tv_sec, record->time.tv_nsec / 1000, record->compressed ? 'C' : 'D'); - if (WARN_ON_ONCE(!hdr)) - return 0; - - len = strlen(hdr); persistent_ram_write(prz, hdr, len); - kfree(hdr); return len; } -- 2.17.1