[PATCH 5.10 03/40] exfat: Avoid allocating upcase table using kcalloc()

Greg Kroah-Hartman
2020-12-23T15:33:34Z

From: Artem Labazov <123321artyom@gmail.com>

commit 9eb78c25327548b905598975aa3ded4ef244b94a upstream.

The table for Unicode upcase conversion requires an order-5 allocation,
which may fail on a highly-fragmented system:

pool-udisksd: page allocation failure: order:5,
mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null),
cpuset=/,mems_allowed=0
CPU: 4 PID: 3756880 Comm: pool-udisksd Tainted: G U
5.8.10-200.fc32.x86_64 #1
Hardware name: Dell Inc. XPS 13 9360/0PVG6D, BIOS 2.13.0 11/14/2019
Call Trace:
dump_stack+0x6b/0x88
warn_alloc.cold+0x75/0xd9
? _cond_resched+0x16/0x40
? __alloc_pages_direct_compact+0x144/0x150
__alloc_pages_slowpath.constprop.0+0xcfa/0xd30
? __schedule+0x28a/0x840
? __wait_on_bit_lock+0x92/0xa0
__alloc_pages_nodemask+0x2df/0x320
kmalloc_order+0x1b/0x80
kmalloc_order_trace+0x1d/0xa0
exfat_create_upcase_table+0x115/0x390 [exfat]
exfat_fill_super+0x3ef/0x7f0 [exfat]
? sget_fc+0x1d0/0x240
? exfat_init_fs_context+0x120/0x120 [exfat]
get_tree_bdev+0x15c/0x250
vfs_get_tree+0x25/0xb0
do_mount+0x7c3/0xaf0
? copy_mount_options+0xab/0x180
__x64_sys_mount+0x8e/0xd0
do_syscall_64+0x4d/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Make the driver use kvcalloc() to eliminate the issue.

Fixes: 370e812b3ec1 ("exfat: add nls operations")
Cc: stable@vger.kernel.org #v5.7+
Signed-off-by: Artem Labazov <123321artyom@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/exfat/nls.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/fs/exfat/nls.c
+++ b/fs/exfat/nls.c
@@ -659,7 +659,7 @@ static int exfat_load_upcase_table(struc
unsigned char skip = false;
unsigned short *upcase_table;

- upcase_table = kcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL);
+ upcase_table = kvcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL);
if (!upcase_table)
return -ENOMEM;

@@ -715,7 +715,7 @@ static int exfat_load_default_upcase_tab
unsigned short uni = 0, *upcase_table;
unsigned int index = 0;

- upcase_table = kcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL);
+ upcase_table = kvcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL);
if (!upcase_table)
return -ENOMEM;

@@ -803,5 +803,5 @@ load_default:

void exfat_free_upcase_table(struct exfat_sb_info *sbi)
{
- kfree(sbi->vol_utbl);
+ kvfree(sbi->vol_utbl);
}