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crypto: sha512-mb - Protect sha512 mb ctx mgr access
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The flusher and regular multi-buffer computation via mcryptd may race with another.
Add here a lock and turn off interrupt to to access multi-buffer
computation state cstate->mgr before a round of computation. This should
prevent the flusher code jumping in.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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@pdxChen @herbertx
pdxChen authored and herbertx committed Feb 11, 2017
1 parent 5d3d9c8 commit c459bd7
Showing 1 changed file with 42 additions and 22 deletions.
64 changes: 42 additions & 22 deletions arch/x86/crypto/sha512-mb/sha512_mb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -221,7 +221,7 @@ static struct sha512_hash_ctx *sha512_ctx_mgr_resubmit
}

static struct sha512_hash_ctx
*sha512_ctx_mgr_get_comp_ctx(struct sha512_ctx_mgr *mgr)
*sha512_ctx_mgr_get_comp_ctx(struct mcryptd_alg_cstate *cstate)
{
/*
* If get_comp_job returns NULL, there are no jobs complete.
Expand All @@ -233,11 +233,17 @@ static struct sha512_hash_ctx
* Otherwise, all jobs currently being managed by the hash_ctx_mgr
* still need processing.
*/
struct sha512_ctx_mgr *mgr;
struct sha512_hash_ctx *ctx;
unsigned long flags;

mgr = cstate->mgr;
spin_lock_irqsave(&cstate->work_lock, flags);
ctx = (struct sha512_hash_ctx *)
sha512_job_mgr_get_comp_job(&mgr->mgr);
return sha512_ctx_mgr_resubmit(mgr, ctx);
ctx = sha512_ctx_mgr_resubmit(mgr, ctx);
spin_unlock_irqrestore(&cstate->work_lock, flags);
return ctx;
}

static void sha512_ctx_mgr_init(struct sha512_ctx_mgr *mgr)
Expand All @@ -246,12 +252,17 @@ static void sha512_ctx_mgr_init(struct sha512_ctx_mgr *mgr)
}

static struct sha512_hash_ctx
*sha512_ctx_mgr_submit(struct sha512_ctx_mgr *mgr,
*sha512_ctx_mgr_submit(struct mcryptd_alg_cstate *cstate,
struct sha512_hash_ctx *ctx,
const void *buffer,
uint32_t len,
int flags)
{
struct sha512_ctx_mgr *mgr;
unsigned long irqflags;

mgr = cstate->mgr;
spin_lock_irqsave(&cstate->work_lock, irqflags);
if (flags & (~HASH_ENTIRE)) {
/*
* User should not pass anything other than FIRST, UPDATE, or
Expand Down Expand Up @@ -351,20 +362,26 @@ static struct sha512_hash_ctx
}
}

return sha512_ctx_mgr_resubmit(mgr, ctx);
ctx = sha512_ctx_mgr_resubmit(mgr, ctx);
spin_unlock_irqrestore(&cstate->work_lock, irqflags);
return ctx;
}

static struct sha512_hash_ctx *sha512_ctx_mgr_flush(struct sha512_ctx_mgr *mgr)
static struct sha512_hash_ctx *sha512_ctx_mgr_flush(struct mcryptd_alg_cstate *cstate)
{
struct sha512_ctx_mgr *mgr;
struct sha512_hash_ctx *ctx;
unsigned long flags;

mgr = cstate->mgr;
spin_lock_irqsave(&cstate->work_lock, flags);
while (1) {
ctx = (struct sha512_hash_ctx *)
sha512_job_mgr_flush(&mgr->mgr);

/* If flush returned 0, there are no more jobs in flight. */
if (!ctx)
return NULL;
break;

/*
* If flush returned a job, resubmit the job to finish
Expand All @@ -378,8 +395,10 @@ static struct sha512_hash_ctx *sha512_ctx_mgr_flush(struct sha512_ctx_mgr *mgr)
* the sha512_ctx_mgr still need processing. Loop.
*/
if (ctx)
return ctx;
break;
}
spin_unlock_irqrestore(&cstate->work_lock, flags);
return ctx;
}

static int sha512_mb_init(struct ahash_request *areq)
Expand Down Expand Up @@ -439,11 +458,11 @@ static int sha_finish_walk(struct mcryptd_hash_request_ctx **ret_rctx,
sha_ctx = (struct sha512_hash_ctx *)
ahash_request_ctx(&rctx->areq);
kernel_fpu_begin();
sha_ctx = sha512_ctx_mgr_submit(cstate->mgr, sha_ctx,
sha_ctx = sha512_ctx_mgr_submit(cstate, sha_ctx,
rctx->walk.data, nbytes, flag);
if (!sha_ctx) {
if (flush)
sha_ctx = sha512_ctx_mgr_flush(cstate->mgr);
sha_ctx = sha512_ctx_mgr_flush(cstate);
}
kernel_fpu_end();
if (sha_ctx)
Expand Down Expand Up @@ -471,11 +490,12 @@ static int sha_complete_job(struct mcryptd_hash_request_ctx *rctx,
struct sha512_hash_ctx *sha_ctx;
struct mcryptd_hash_request_ctx *req_ctx;
int ret;
unsigned long flags;

/* remove from work list */
spin_lock(&cstate->work_lock);
spin_lock_irqsave(&cstate->work_lock, flags);
list_del(&rctx->waiter);
spin_unlock(&cstate->work_lock);
spin_unlock_irqrestore(&cstate->work_lock, flags);

if (irqs_disabled())
rctx->complete(&req->base, err);
Expand All @@ -486,14 +506,14 @@ static int sha_complete_job(struct mcryptd_hash_request_ctx *rctx,
}

/* check to see if there are other jobs that are done */
sha_ctx = sha512_ctx_mgr_get_comp_ctx(cstate->mgr);
sha_ctx = sha512_ctx_mgr_get_comp_ctx(cstate);
while (sha_ctx) {
req_ctx = cast_hash_to_mcryptd_ctx(sha_ctx);
ret = sha_finish_walk(&req_ctx, cstate, false);
if (req_ctx) {
spin_lock(&cstate->work_lock);
spin_lock_irqsave(&cstate->work_lock, flags);
list_del(&req_ctx->waiter);
spin_unlock(&cstate->work_lock);
spin_unlock_irqrestore(&cstate->work_lock, flags);

req = cast_mcryptd_ctx_to_req(req_ctx);
if (irqs_disabled())
Expand All @@ -504,7 +524,7 @@ static int sha_complete_job(struct mcryptd_hash_request_ctx *rctx,
local_bh_enable();
}
}
sha_ctx = sha512_ctx_mgr_get_comp_ctx(cstate->mgr);
sha_ctx = sha512_ctx_mgr_get_comp_ctx(cstate);
}

return 0;
Expand All @@ -515,16 +535,17 @@ static void sha512_mb_add_list(struct mcryptd_hash_request_ctx *rctx,
{
unsigned long next_flush;
unsigned long delay = usecs_to_jiffies(FLUSH_INTERVAL);
unsigned long flags;

/* initialize tag */
rctx->tag.arrival = jiffies; /* tag the arrival time */
rctx->tag.seq_num = cstate->next_seq_num++;
next_flush = rctx->tag.arrival + delay;
rctx->tag.expire = next_flush;

spin_lock(&cstate->work_lock);
spin_lock_irqsave(&cstate->work_lock, flags);
list_add_tail(&rctx->waiter, &cstate->work_list);
spin_unlock(&cstate->work_lock);
spin_unlock_irqrestore(&cstate->work_lock, flags);

mcryptd_arm_flusher(cstate, delay);
}
Expand Down Expand Up @@ -565,7 +586,7 @@ static int sha512_mb_update(struct ahash_request *areq)
sha_ctx = (struct sha512_hash_ctx *) ahash_request_ctx(areq);
sha512_mb_add_list(rctx, cstate);
kernel_fpu_begin();
sha_ctx = sha512_ctx_mgr_submit(cstate->mgr, sha_ctx, rctx->walk.data,
sha_ctx = sha512_ctx_mgr_submit(cstate, sha_ctx, rctx->walk.data,
nbytes, HASH_UPDATE);
kernel_fpu_end();

Expand Down Expand Up @@ -628,7 +649,7 @@ static int sha512_mb_finup(struct ahash_request *areq)
sha512_mb_add_list(rctx, cstate);

kernel_fpu_begin();
sha_ctx = sha512_ctx_mgr_submit(cstate->mgr, sha_ctx, rctx->walk.data,
sha_ctx = sha512_ctx_mgr_submit(cstate, sha_ctx, rctx->walk.data,
nbytes, flag);
kernel_fpu_end();

Expand Down Expand Up @@ -677,8 +698,7 @@ static int sha512_mb_final(struct ahash_request *areq)
/* flag HASH_FINAL and 0 data size */
sha512_mb_add_list(rctx, cstate);
kernel_fpu_begin();
sha_ctx = sha512_ctx_mgr_submit(cstate->mgr, sha_ctx, &data, 0,
HASH_LAST);
sha_ctx = sha512_ctx_mgr_submit(cstate, sha_ctx, &data, 0, HASH_LAST);
kernel_fpu_end();

/* check if anything is returned */
Expand Down Expand Up @@ -940,7 +960,7 @@ static unsigned long sha512_mb_flusher(struct mcryptd_alg_cstate *cstate)
break;
kernel_fpu_begin();
sha_ctx = (struct sha512_hash_ctx *)
sha512_ctx_mgr_flush(cstate->mgr);
sha512_ctx_mgr_flush(cstate);
kernel_fpu_end();
if (!sha_ctx) {
pr_err("sha512_mb error: nothing got flushed for"
Expand Down

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