Commit 2ddb69f6 authored by Cole Leavitt's avatar Cole Leavitt Committed by Kees Cook
Browse files

pstore/ram: fix resource leak when ioremap() fails 



In persistent_ram_iomap(), ioremap() or ioremap_wc() may return NULL on
failure. Currently, if this happens, the function returns NULL without
releasing the memory region acquired by request_mem_region().

This leads to a resource leak where the memory region remains reserved
but unusable.

Additionally, the caller persistent_ram_buffer_map() handles NULL
correctly by returning -ENOMEM, but without this check, a NULL return
combined with request_mem_region() succeeding leaves resources in an
inconsistent state.

This is the ioremap() counterpart to commit 05363abc ("pstore:
ram_core: fix incorrect success return when vmap() fails") which fixed
a similar issue in the vmap() path.

Fixes: 404a6043 ("staging: android: persistent_ram: handle reserving and mapping memory")
Signed-off-by: default avatarCole Leavitt <cole@unwrap.rs>
Link: https://patch.msgid.link/20260225235406.11790-1-cole@unwrap.rs


Signed-off-by: default avatarKees Cook <kees@kernel.org>
parent b22462c7

fs/pstore/ram_core.c

+4 −0
Original line number Diff line number Diff line
@@ -487,6 +487,10 @@ static void *persistent_ram_iomap(phys_addr_t start, size_t size, 
	else

		va = ioremap_wc(start, size);



	/* We must release the mem region if ioremap fails. */

	if (!va)

		release_mem_region(start, size);



	/*

	 * Since request_mem_region() and ioremap() are byte-granularity

	 * there is no need handle anything special like we do when the