From 0e34d0945ed16aeb72c863be4efe4cd0c62f9c53 Mon Sep 17 00:00:00 2001 From: Tim Gardner Date: Mon, 11 Feb 2013 14:34:32 -0700 Subject: [PATCH] drm/radeon: Avoid NULL pointer dereference from atom_index_iio() allocation failure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Smatch anlysis: drivers/gpu/drm/radeon/atom.c:1242 atom_index_iio() error: potential null dereference 'ctx->iio'. (kzalloc returns null) Also cleaned up some checks before calls to kfree(). kfree(NULL) is OK. Cc: David Airlie Cc: Alex Deucher Cc: "Michel Dänzer" Cc: Dave Airlie Cc: "Christian König" Cc: Jerome Glisse Cc: dri-devel@lists.freedesktop.org Signed-off-by: Tim Gardner Signed-off-by: Alex Deucher --- drivers/gpu/drm/radeon/atom.c | 9 +++++++-- drivers/gpu/drm/radeon/radeon_device.c | 9 ++++++++- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c index 5ce9bf51a8de..46a9c3772850 100644 --- a/drivers/gpu/drm/radeon/atom.c +++ b/drivers/gpu/drm/radeon/atom.c @@ -1238,6 +1238,8 @@ static int atom_iio_len[] = { 1, 2, 3, 3, 3, 3, 4, 4, 4, 3 }; static void atom_index_iio(struct atom_context *ctx, int base) { ctx->iio = kzalloc(2 * 256, GFP_KERNEL); + if (!ctx->iio) + return; while (CU8(base) == ATOM_IIO_START) { ctx->iio[CU8(base + 1)] = base + 2; base += 2; @@ -1287,6 +1289,10 @@ struct atom_context *atom_parse(struct card_info *card, void *bios) ctx->cmd_table = CU16(base + ATOM_ROM_CMD_PTR); ctx->data_table = CU16(base + ATOM_ROM_DATA_PTR); atom_index_iio(ctx, CU16(ctx->data_table + ATOM_DATA_IIO_PTR) + 4); + if (!ctx->iio) { + atom_destroy(ctx); + return NULL; + } str = CSTR(CU16(base + ATOM_ROM_MSG_PTR)); while (*str && ((*str == '\n') || (*str == '\r'))) @@ -1335,8 +1341,7 @@ int atom_asic_init(struct atom_context *ctx) void atom_destroy(struct atom_context *ctx) { - if (ctx->iio) - kfree(ctx->iio); + kfree(ctx->iio); kfree(ctx); } diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c index 6a36f4b67680..9f02fdd68f51 100644 --- a/drivers/gpu/drm/radeon/radeon_device.c +++ b/drivers/gpu/drm/radeon/radeon_device.c @@ -758,6 +758,11 @@ int radeon_atombios_init(struct radeon_device *rdev) atom_card_info->pll_write = cail_pll_write; rdev->mode_info.atom_context = atom_parse(atom_card_info, rdev->bios); + if (!rdev->mode_info.atom_context) { + radeon_atombios_fini(rdev); + return -ENOMEM; + } + mutex_init(&rdev->mode_info.atom_context->mutex); radeon_atom_initialize_bios_scratch_regs(rdev->ddev); atom_allocate_fb_scratch(rdev->mode_info.atom_context); @@ -777,9 +782,11 @@ void radeon_atombios_fini(struct radeon_device *rdev) { if (rdev->mode_info.atom_context) { kfree(rdev->mode_info.atom_context->scratch); - kfree(rdev->mode_info.atom_context); } + kfree(rdev->mode_info.atom_context); + rdev->mode_info.atom_context = NULL; kfree(rdev->mode_info.atom_card_info); + rdev->mode_info.atom_card_info = NULL; } /* COMBIOS */